Disc cartridge having a rotatable shutter

ABSTRACT

A disc cartridge according to the present invention includes a cartridge body and a shutter. The cartridge body includes a disc storage portion, a chucking opening and a head opening. The disc storage portion stores a disc, having first and second sides, therein so that the disc is rotatable in the disc storage portion. The shutter is supported to, and rotatable with respect to, the cartridge body between the second side of the disc and the bottom of the disc storage portion so as to expose or cover the chucking opening and the head opening.

This is a continuation of International Application PCT/JP02/00110 andinternational filing date of Jan. 10, 2002.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a disc cartridge for use to store adisk-shaped signal storage medium such as an optical disc or a magneticdisk therein in a rotatable state.

2. Description of the Related Art

Various disc cartridges have been proposed as protective cases fordisk-shaped signal storage media.

For example, Japanese Laid-Open Publication No. 9-153264 discloses adisc cartridge in which a disk-shaped storage medium having a single ordouble signal recording sides (which will be herein referred to as a“disc” simply) is completely enclosed in a disc storage portion. Thedisc storage portion is defined inside a cartridge body that is made upof upper and lower halves. The cartridge body includes chucking openingsand a head opening. The chucking openings allow the turntable of aspindle motor and a clamper to chuck a disc inserted, while the headopening allows a head to read and/or write a signal from/on the disc.The lower one of the chucking openings is continuous with the headopening. Accordingly, while the operator carries such a cartridge, dusteasily enters the inside of the cartridge through these openings and thedisc is also easily soiled with finger marks. For that reason, the disccartridge further includes a shutter for closing these openings up.

A disc cartridge having such a structure, however, has the followingdrawbacks. Firstly, such a disc cartridge cannot be so thin. This isbecause the disc storage space, defined between the upper and lowerhalves, should be thick enough to allow a disc drive to accurately reador write a signal (or information) from/onto the disc stored in such adisc cartridge. The reasons why the disc storage space should berelatively thick include the expected flutter or warp of the disc beingrotated and an error that may occur in disposing the disc cartridge at apredetermined position inside the disc drive.

Secondly, the shutter for closing up these chucking and head openings atthe same time cannot be formed at a low cost, thus increasing theoverall manufacturing cost of such a disc cartridge. The reason is asfollows. Specifically, the lower half of the disc cartridge is providedwith an opening for the turntable of the spindle motor and a headopening, while the upper half thereof is provided with another openingfor the clamper. Thus, to close these three openings up at a time, theshutter needs to be formed in a U-shape, which is not so cheap to make.

Thirdly, the disc stored inside such a disc cartridge is not fixed inmany cases, thus possibly causing dust or fine particle deposition andscratching problems. Specifically, although a disc with a metal hub canbe attracted and fixed in position via a magnetic force so as not tomove inconstantly, an optical disc with no hub, e.g., a CD or a DVD, isnormally not fixed, and movable freely, inside the disc cartridge.Accordingly, when the shutter of the disc cartridge is opened inside thedisc drive, dust may enter the cartridge through its openings and bedeposited on the disc easily. Also, if the disc is shaken so much as tocontact with the inner walls of the disc cartridge, the signal recordingside of the disc may get scratched or fine particles may be stirred upand deposited on the disc.

SUMMARY OF THE INVENTION

In order to overcome the problems described above, an object of thepresent invention is to provide a disc cartridge that has a reducedthickness and a simplified, much less expensive shutter for asingle-sided disc, in particular. Another object of the presentinvention is to provide a disc cartridge that can drastically reduce thedust to be deposited on the disc stored therein by getting the discfirmly held inside the disc cartridge and eliminating the inconstantmovement of the disc. A third object of the present invention is toprovide a disc cartridge of a good design by displaying the label sideof the disc stored therein.

A disc cartridge according to the present invention includes a cartridgebody, a shutter and a disk holding member. The cartridge body includes:a disc storage portion that stores a disc, having first and secondsides, therein so that the disc is rotatable in the disc storage portionand that the first side of the disc is exposed; a chucking opening thatis formed on the bottom of the disc storage portion so as to get thedisc chucked externally; and a head opening that is also formed on thebottom of the disc storage portion so as to allow a head, which readsand/or writes a signal from/on the second side of the disc, to accessthe second side of the disc. The shutter is supported to, and movablewith respect to, the cartridge body so as to expose or cover at leastthe head opening. The disc holding member holds or releases the disconto/from the cartridge body.

The disc holding member preferably holds the disc by pressing the secondside of the disc against the bottom of the disc storage portion. Also,the disc holding member preferably brings at least the outer peripheryand its surrounding portion of the second side of the disc into contactwith the bottom of the disc storage portion.

In one embodiment, the disc cartridge includes a plurality of discholding members, including the disc holding member. Each of the discholding members is disposed so that a portion thereof is located on theouter periphery of the disc. At least two of the disc holding membersmay have the same shape. The disc holding members may be interlockedtogether to perform an operation of holding or releasing the disc.

In one embodiment, the disc holding member is an ellipsoidal ring madeof an elastic material. The ring is deformable so as to have an insidediameter that is greater than the diameter of the disc.

The disc holding member preferably has a slope that contacts with thedisc. Preferably, by disposing the disc holding member on the cartridgebody so that the slope of the disc holding member overhangs the outerperiphery of the disc, the slope is brought into contact with a sidesurface or edge of the disc, thereby gripping the disc thereon, pressingthe disc against the bottom of the disc storage portion, and holding thedisc thereon.

In one embodiment of the disc cartridge, the cartridge body includes apair of positioning holes that engages with positioning pins. Thepositioning pins are provided for a disc drive to define an insertposition when the disc cartridge is loaded into the disk drive.

In another embodiment of the disc cartridge, the disc cartridge bodyincludes a concave portion that engages with a convex portion providedfor a disk drive and that is used to prevent the disc cartridge frombeing inserted erroneously.

In another embodiment of the disc cartridge, the disc cartridge bodyincludes a concave portion that engages with a convex portion providedfor a disk drive when the disc cartridge is inserted into the diskdrive.

While the disc cartridge is being loaded into, and fixed at the insertposition inside, the disk drive, the disc holding member may release thedisc that the disc holding member has held thereon.

Alternatively, as the positioning pins of the disk drive engage with thepositioning holes of the disc cartridge, the disc holding member mayrelease the disc that the disc holding member has held thereon.

As another alternative, as the convex portion that is provided for thedisk drive to prevent the disc cartridge from being inserted erroneouslyengages with the concave portion provided for the disc cartridge, thedisc holding member may release the disc that the disc holding memberhas held thereon.

As still another alternative, as the convex portion provided for thedisk drive engages with the concave portion of the disc cartridge, thedisc holding member may release the disc that the disc holding memberhas held thereon.

The disc cartridge may include a pair of disc holding members, eachholding the disc thereon at two points. Each of the pair of disc holdingmembers may engage with one of the pair of positioning pins provided forthe disk drive, thereby performing the operation of holding or releasingthe disc at the two points of the disc holding member substantiallysimultaneously.

The shutter may include a member that engages with the disc holdingmember so that the disc having been held is released as the shutter isgoing to be closed or opened.

The disc holding member may include a deformable elastic portion thathas been molded so as to form an integral part of the cartridge body.The disc may be either held or released by deforming the elasticportion.

In one embodiment, the disc cartridge further includes a lockingmechanism for fixing and supporting disc holding member onto thecartridge body while the disc holding member is holding the discthereon.

In one embodiment of the disc cartridge, one of the disc holding membersincludes a locking mechanism for fixing and supporting the disc holdingmembers onto the cartridge body while the disc holding members areholding the disc thereon.

In one embodiment of the disc cartridge, the disc holding member furtherincludes a stopper portion for preventing the disc from dropping downfrom the storage portion of the disc cartridge when the disc holdingmember releases the disc.

In one embodiment, the head opening reaches a side surface of thecartridge body.

In one embodiment, the disc cartridge includes a protective layer forpreventing the disc from getting scratched on the bottom of the discstorage portion that contacts with the second side of the disc. Theprotective layer is preferably selected from the group consisting of ananti-scratching nonwoven fabric, a dustproof nonwoven fabric, ananti-scratching coating layer and a dustproof coating layer.

In one embodiment, the disc cartridge further includes a brush or a dustwiping member on one side of the shutter that moves across the headopening when the shutter is opened or closed.

In one embodiment, the dirt of the disc is removed by rotating the discwhile the disc is in contact with the protective layer that is providedon the bottom of the disc storage portion.

In one embodiment, the disc cartridge further includes a discholding/interlocking member, which is stored inside the disc storageportion to synchronize opening or closing of the shutter with theholding or releasing operation by the disk holding member.

In one embodiment, the shutter is substantially in a fan shape and isheld so as to rotate and slide around the chucking opening, and openingor closing of the shutter is synchronized with the holding or releasingoperation by the disk holding member.

The disk holding member preferably holds the disc thereon by pressing atleast the outer periphery and its surrounding portion of the second sideof the disc against the bottom of the disc storage portion, the discholding/interlocking member or the shutter.

In one embodiment, the disc cartridge includes a plurality of discholding members, including the disc holding member. Each of the discholding members is disposed so that a portion thereof is located on theouter periphery of the disc.

The disc holding member preferably has a slope that contacts with thedisc. Preferably, by disposing the disc holding member on the cartridgebody so that the slope of the disc holding member overhangs the outerperiphery of the disc, the slope is brought into contact with a sidesurface or edge of the disc, thereby gripping the disc thereon, pressingthe disc against the bottom of the disc storage portion and holding thedisc thereon.

In one embodiment, the disc holding member includes an elastic portionthat has been molded so as to form an integral part of the cartridgebody and that is deformable in such a manner as to either hold orrelease the disc.

In one embodiment, the disc holding member further includes a stopperportion for preventing the disc from dropping down from the storageportion of the disc cartridge when the disc holding member releases thedisc.

In one embodiment, when the shutter opens to expose the head opening,the disk holding member releases the disc.

In one embodiment, the disc holding/interlocking member is substantiallyin a fan shape.

In one embodiment, the disc storage portion includes: a first innersurface to be the bottom of the disc storage portion; and a second innersurface that is substantially in a cylindrical shape and that surroundsthe outer periphery of the disc when the disc is stored in the discstorage portion.

In one embodiment, the shutter is provided outside of the disccartridge.

In one embodiment, the shutter is provided on the bottom of the discstorage portion.

In one embodiment, the shutter exposes or covers the chucking opening.

In one embodiment, the number of the shutters is one.

Another disc cartridge according to the present invention includes acartridge body and a shutter. The cartridge body includes: a discstorage portion that stores a disc, having first and second sides,therein so that the disc is rotatable in the disc storage portion; achucking opening that is formed on the bottom of the disc storageportion so as to get the disc chucked externally; and a head openingthat is also formed on the bottom of the disc storage portion so as toallow a head, which reads and/or writes a signal from/on the second sideof the disc, to access the second side of the disc. The shutter issupported to, and movable with respect to, the cartridge body betweenthe second side of the disc and the bottom of the disc storage portionso as to expose or cover the chucking opening and the head opening.

Still another disc cartridge according to the present invention includesa cartridge body, a shutter and a disk holding portion. The cartridgebody includes: a disc storage portion that stores a disc, having firstand second sides, therein so that the disc is rotatable in the discstorage portion; a chucking opening that is formed on the bottom of thedisc storage portion so as to get the disc chucked externally; and ahead opening that is also formed on the bottom of the disc storageportion so as to allow a head, which reads and/or writes a signalfrom/on the second side of the disc, to access the second side of thedisc. The shutter is supported to, and movable with respect to, thecartridge body so as to expose or cover the chucking opening and thehead opening. The disc holding portion fixes the disc onto the shutteror the cartridge body when the shutter covers the chucking opening andthe head opening synchronously with opening or closing of the shutter.

In one embodiment, the disc storage portion includes: a first innersurface to be the bottom of the disc storage portion; a second innersurface that is substantially in a cylindrical shape and that surroundsthe outer periphery of the disc when the disc is stored in the discstorage portion; and a disc window through which the disc is inserted orremoved. The disc storage portion stores the disc therein so that oneside of the disc is exposed inside the disc window.

In one embodiment of the disc cartridge, the shutter includes a discholding portion for fixing the disc onto the shutter when the shuttercovers the chucking opening and the head opening synchronously withopening or closing of the shutter.

In one embodiment, the disk holding portion is provided as a portion ofthe shutter.

In one embodiment, the disc cartridge includes multiple disk holdingportions, which include the disk holding portion and which are disposedon the shutter so as to hold the outer periphery and its surroundingportion of the disc.

In one embodiment, the disc is brought into plane contact with theshutter by the disk holding portion.

In one embodiment, the disk holding portion has a downwardly taperedslope, grips the disc thereon by bringing the slope into contact with aside surface or an edge of the disc, and holds the disc-with respect tothe cartridge body by bringing the disc into plane contact with theshutter.

In one embodiment, the disc cartridge further includes a lockingmechanism for fixing and supporting the shutter onto the cartridge bodywhile the shutter covers the chucking opening and the head opening. Thesecond inner surface is preferably partially notched so as not tointerfere with the operation of the shutter.

In one embodiment of the disc cartridge, the cartridge body includes ashutter storage portion that stores a portion of the shutter thereinwhile the shutter exposes the chucking opening and the head opening.

In one embodiment, the disc cartridge further includes multiple stopperportions that protrude toward the disc window to prevent the disc fromdropping down through the disc window. The stopper portions may move ina thickness direction of the disc cartridge as the shutter is going tobe opened or closed.

In one embodiment, the disc cartridge may include a plurality ofshutters, including the shutter. The plurality of shutters may cooperatewith each other to expose or cover the chucking opening and the headopening.

In one embodiment, one of the shutters is provided with a lockingmechanism that fixes the shutters onto the cartridge body while theshutters are covering the chucking opening and the head opening.

In one embodiment, the shutters cover the chucking opening and the headopening by partially overlapping with each other in a thicknessdirection of the shutters.

In one embodiment, the disc cartridge includes an erroneous insertionpreventing mechanism for the disc cartridge.

In one embodiment, the head opening reaches a side surface of thecartridge body.

In one embodiment, the shutters rotate on multiple rotation shafts thatare provided on the disc cartridge body. The rotation shafts arepreferably provided in respective portions of the disc cartridge bodyother than the disc storage portion. Also, the head opening may reach aside surface of the cartridge body, and the rotation shafts may beprovided near another side surface thereof that is opposed to the formerside surface.

In one embodiment, the shutters include interlocking portions that openor close the shutters while being interlocked with each other. Theinterlocking portions may be cam-shaped or gear-shaped portions that areprovided for the respective shutters. Alternatively, the interlockingportions may also be belts or links.

In one embodiment, the disc cartridge further includes an elastic memberthat applies a force in such a manner as to keep the shutters opened orclosed. The elastic member is preferably provided in a portion of thedisc cartridge body other than the disc storage portion. The elasticmember may have been molded so as to form an integral part of theshutter.

In one embodiment, the stopper members may be removable and may havebeen molded so as to form integral parts of the cartridge body.

In one embodiment, the stopper members are provided so as to beremovable from the cartridge body.

In one embodiment, the disc cartridge includes a protective layer forpreventing the disc from getting scratched on a portion of the shutterthat contacts with the second side of the disc. The protective layer ispreferably selected from the group consisting of an anti-scratchingnonwoven fabric, a dustproof nonwoven fabric, an anti-scratching coatinglayer and a dustproof coating layer.

In one embodiment, the dirt of the disc is removed by rotating the discwhile the disc is in plane contact with the shutter. Alternatively, thedirt of the disc may also be removed by the opening or closing operationthat is performed by the shutter to expose or cover the chucking openingand the head opening.

In one embodiment, the erroneous insertion preventing mechanism includesconvex portions or concave portions that are provided on outer sidesurfaces of the cartridge body so as to be asymmetrically disposed in adirection in which the disc cartridge is inserted into an externalapparatus.

In one embodiment, the locking mechanism includes: a locking hole thatis formed through the disc cartridge body; and a locking protrusionportion that is provided for the shutter so as to engage with thelocking hole when the shutter is located at such a position as to coverthe chucking opening and the head opening.

In one embodiment, the locking protrusion portion is provided for theshutter by way of an elastic member and the elastic member applies aforce to the locking protrusion portion toward the locking hole andmakes the locking protrusion portion engage with the locking hole.

In one embodiment, the locking mechanism includes: a locking hole thatis formed through the disc cartridge body; a locking protrusion portionthat is provided so as to engage with the locking hole when the shutteris located at such a position as to cover the chucking opening and thehead opening; a locking lever provided for the disc cartridge body; afirst convex portion or first concave portion that is formed on thelocking lever; and a second concave portion or second convex portionthat is formed on the shutter so as to engage with the first convexportion or first concave portion at the covering position.

The locking lever may be provided for the disc cartridge body by way ofan elastic member. The elastic member may apply a force to the lockingprotrusion portion toward the locking hole to make the lockingprotrusion portion engage with the locking hole. The elastic member mayalso apply a force to the first convex portion or first concave portiontoward the second concave portion or second convex portion to make thefirst convex portion or first concave portion engage with the secondconcave portion or second convex portion. Also, the locking protrusionportion and the elastic member may have been molded so as to formintegral parts of the shutter. Alternatively, the locking lever and theelastic member may have been molded so as to form integral parts of thedisc cartridge body.

In one embodiment, the shutter includes a convex portion that isprovided for the shutter so as to protrude into a center hole of thedisc while the shutter is keeping plane contact with the disc andcovering the chucking opening and the head opening. As the shutter isgoing to be opened, the convex portion lifts the disc in a thicknessdirection of the cartridge while contacting with the lower surface ofthe disc, thereby getting the disc and the shutter out of plane contactfrom each other.

In one embodiment, the disc cartridge includes a plurality of shutters,including the shutter. Each of the shutters includes a convex portionthat is provided for the shutter so as to protrude into a center hole ofthe disc while the shutters are keeping plane contact with the disc andcovering the chucking opening and the head opening. As the shutters aregoing to be opened, the convex portions lift the disc in a thicknessdirection of the cartridge while contacting with the lower surface ofthe disc, thereby getting the disc and the shutters out of plane contactfrom each other.

The convex portion may have a shape that is selected from the groupconsisting of a spherical shape, a conical shape, a ring shape and ashape made up of multiple spheres.

In one embodiment, the stopper members form integral parts of theshutter. The stopper members may be formed integrally with the shutterby way of flexible members or elastic members. Each of the stoppermembers may include a convex portion or a concave portion. An innersidewall or an inner upper wall of the cartridge body may include aguide concave portion or a guide convex portion that engages with theconvex portion or the concave portion of the stopper member. The stoppermembers may move in the thickness direction of the disc cartridge as theshutter is going to be opened or closed.

In one embodiment, the stopper members form integral parts of thecartridge body. The stopper members may be formed integrally with thecartridge body by way of elastic members. Each of the stopper membersmay be an elastic member that is obtained by separating a portion of thecartridge body via a slit. Each of the stopper members may include afirst convex portion or a first sloped portion while the shutter mayinclude a second sloped portion or a second convex portion. The firstconvex portion and the second sloped portion or the first sloped portionand the second convex portion may contact with each other.

Also, when the shutter exposes the chucking opening and the headopening, the first convex portion and the second sloped portion or thefirst sloped portion and the second convex portion may contact with eachother.

A concave portion, which engages with the second convex portion or thefirst convex portion, may be provided near the first sloped portion orthe second sloped portion.

In one embodiment, the stopper members hold the disc onto the cartridgebody by pressing the disc in the thickness direction thereof andbringing the disc into plane contact with the shutter while the shuttercovers the chucking opening and the head opening.

In one embodiment, an opening/closing lever for use to open or close theshutters and a locking mechanism for use to fix and support the shuttersto the cartridge body when the shutters are located in such a positionas to cover the chucking opening and the head opening are provided fortwo different ones of the shutters.

Still another disc cartridge according to the present invention includesa cartridge body, a shutter and a disc holding portion. The cartridgebody includes a disc storage portion, a chucking opening and a headopening. The disc storage portion stores a disc, having first and secondsides, therein so that the disc is rotatable in the disc storage portionand that the first side of the disc is exposed. The chucking opening isformed on the bottom of the disc storage portion so as to get the discchucked externally. The head opening is also formed on the bottom of thedisc storage portion so as to allow a head, which reads and/or writes asignal from/on the second side of the disc, to access the second side ofthe disc. The shutter is supported, and movable with respect to thecartridge body, between the second side of the disc and the bottom ofthe disc storage portion so as to expose or cover the chucking and headopenings, and defines a hole in a region corresponding to a center holeof the disc while the shutter is closed. The disc holding portion isprovided for the shutter, presses the disc against the shutter, andholds the disc thereon while the chucking and head openings are coveredwith the shutter.

In one embodiment, the hole of the shutter has a diameter that isapproximately equal to that of the center hole of the disc.

Yet another disc cartridge according to the present invention includes acartridge body, a shutter, a disc holding portion and a rim. Thecartridge body includes a disc storage portion, a chucking opening and ahead opening. The disc storage portion stores a disc, having first andsecond sides, therein so that the disc is rotatable in the disc storageportion and that the first side of the disc is exposed. The chuckingopening is formed on the bottom of the disc storage portion so as to getthe disc chucked externally. The head opening is also formed on thebottom of the disc storage portion so as to allow a head, which readsand/or writes a signal from/on the second side of the disc, to accessthe second side of the disc. The shutter is supported, and movable withrespect to the cartridge body, between the second side of the disc andthe bottom of the disc storage portion so as to expose or cover thechucking and head openings. The disc holding portion is provided for theshutter, presses the disc against the shutter, and holds the discthereon while the chucking and head openings are covered with theshutter. The rim extends from an inner side surface of the disc storageportion toward the center of the disc and contacts with an outer edgeportion of the disc while the shutter is closed.

In one embodiment, the shutter defines a hole in an area correspondingto a center hole of the disc while the shutter is closed. The rim maycontact with the second side of the disc. The cartridge body may have agap between the rim and the inner lower surface of the disc storageportion so that a portion of the shutter is stored in the gap while thechucking and head openings are exposed by the shutter.

In one embodiment, the disc cartridge further includes a convex portionaround the hole of the shutter. The convex portion contacts with thesecond side of the disc while the chucking and head openings are coveredwith the shutter.

In one embodiment, the shutter includes a convex portion that closes agap between the second side of the disc and the shutter while theshutter is closed. The convex portion may be located closer to thecenter of the disc storage portion than the rim is while the chuckingand head openings are exposed by the shutter. The convex portion may bea protective layer that prevents the disc from getting scratched.

In one embodiment, a protective layer is provided on the rim to preventthe disc from getting scratched. The protective layer may be selectedfrom the group consisting of an anti-scratching nonwoven fabric, adustproof nonwoven fabric, an anti-scratching coating layer and adustproof coating layer.

In one embodiment, the convex portion forms an integral part of theshutter.

Yet another disc cartridge according to the present invention includes acartridge body, a pair of shutters and a disc holding portion. Thecartridge body includes a disc storage portion, a chucking opening and ahead opening. The disc storage portion stores a disc, having first andsecond sides, therein so that the disc is rotatable in the disc storageportion and that the first side of the disc is exposed. The chuckingopening is formed on the bottom of the disc storage portion so as to getthe disc chucked externally. The head opening is also formed on thebottom of the disc storage portion so as to allow a head, which readsand/or writes a signal from/on the second side of the disc, to accessthe second side of the disc. The pair of shutters is supported, andmovable with respect to the cartridge body, between the second side ofthe disc and the bottom of the disc storage portion so as to expose orcover the chucking and head openings. The disc holding portion isprovided for the shutters, presses the disc against the shutters, andholds the disc thereon while the chucking and head openings are coveredwith the shutters. The head opening reaches a side surface of thecartridge body. An operating portion for use to open and close theshutters is provided for the shutters and is located inside the headopening.

Yet another disc cartridge according to the present invention includes acartridge body, a pair of shutters and a disc holding portion. Thecartridge body includes a disc storage portion, a chucking opening and ahead opening. The disc storage portion stores a disc, having first andsecond sides, therein so that the disc is rotatable in the disc storageportion and that the first side of the disc is exposed. The chuckingopening is formed on the bottom of the disc storage portion so as to getthe disc chucked externally. The head opening is also formed on thebottom of the disc storage portion so as to allow a head, which readsand/or writes a signal from/on the second side of the disc, to accessthe second side of the disc. The pair of shutters is supported, andmovable with respect to the cartridge body, between the second side ofthe disc and the bottom of the disc storage portion so as to expose orcover the chucking and head openings. The disc holding portion isprovided for the shutters, presses the disc against the shutters, andholds the disc thereon while the chucking and head openings are coveredwith the shutters. The shutters have first and second pairs of contactsurfaces. Each pair of contact surfaces contacts with each other. Thefirst and second pairs are not aligned with each other.

In one embodiment, the contact surfaces of each of the first and secondpairs are sloped, and overlap with each other, in a thickness directionof the disc.

Yet another disc cartridge according to the present invention includes acartridge body, a pair of shutters and a number of disc holdingportions. The cartridge body includes a disc storage portion, a chuckingopening and a head opening. The disc storage portion stores a disc,having first and second sides, therein so that the disc is rotatable inthe disc storage portion and that the first side of the disc is exposed.The chucking opening is formed on the bottom of the disc storage portionso as to get the disc chucked externally. The head opening is alsoformed on the bottom of the disc storage portion so as to allow a head,which reads and/or writes a signal from/on the second side of the disc,to access the second side of the disc. The pair of shutters issupported, and movable with respect to the cartridge body, between thesecond side of the disc and the bottom of the disc storage portion so asto expose or cover the chucking and head openings. The disc holdingportions are provided for the shutters, press the disc against theshutters, and hold the disc thereon while the chucking and head openingsare covered with the shutters. At least one of the disc holding portionsis movable toward the center of the disc storage portion with respect toone of the shutters.

Yet another disc cartridge according to the present invention includes acartridge body, a pair of shutters, a number of disc holding portionsand a number of stopper members. The cartridge body includes a discstorage portion, a chucking opening and a head opening. The disc storageportion stores a disc, having first and second sides, therein so thatthe disc is rotatable in the disc storage portion and that the firstside of the disc is exposed. The chucking opening is formed on thebottom of the disc storage portion so as to get the disc chuckedexternally. The head opening is also formed on the bottom of the discstorage portion so as to allow a head, which reads and/or writes asignal from/on the second side of the disc, to access the second side ofthe disc. The pair of shutters is supported, and movable with respect tothe cartridge body, between the second side of the disc and the bottomof the disc storage portion so as to expose or cover the chucking andhead openings. The disc holding portions are provided for the shutters.Each of the disc holding portions has a downwardly tapered slope thatpresses the disc against the shutters and holds the disc thereon whilethe chucking and head openings are covered with the shutters. Each ofthe stopper members has a disc contact surface that prevents the discfrom dropping down from the disc storage portion and provided for thecartridge body to protrude over the disc. A portion of the slope of eachof the disc holding portions is located over the contact surface of eachof the stopper members.

In one embodiment, the pair of shutters is locked together while closed.

In one embodiment, the disc cartridge further includes a shutter contactportion that regulates the positions of the shutters being closed.

Yet another disc cartridge according to the present invention includes acartridge body, a pair of shutters and a number of disc holdingportions. The cartridge body includes a disc storage portion, a chuckingopening and a head opening. The disc storage portion stores a disc,having first and second sides, therein so that the disc is rotatable inthe disc storage portion and that the first side of the disc is exposed.The chucking opening is formed on the bottom of the disc storage portionso as to get the disc chucked externally. The head opening is alsoformed on the bottom of the disc storage portion so as to allow a head,which reads and/or writes a signal from/on the second side of the disc,to access the second side of the disc. The pair of shutters issupported, and movable with respect to the cartridge body, between thesecond side of the disc and the bottom of the disc storage portion so asto expose or cover the chucking and head openings. The disc holdingportions are provided for the shutters, press the disc against theshutters, and hold the disc thereon while the chucking and head openingsare covered with the shutters. Each of the disc holding portionsincludes a first portion with a first height and a second portion with asecond height that is lower than the first height. An upper surface ofthe cartridge body has a recessed portion to receive the top of thefirst portion of each disc holding portion that moves as the shuttersare going to be opened or closed. The recessed portion is thinner thananother portion of the upper surface of the cartridge body under whichthe second portion of the disc holding portion moves.

In one embodiment, as the shutters are going to be closed, the firstportion contacts with the disc earlier than the second portion.

Yet another disc cartridge according to the present invention includes acartridge body, a pair of shutters, a number of disc holding portionsand a stopper member. The cartridge body includes a disc storageportion, a chucking opening and a head opening. The disc storage portionstores a disc, having first and second sides, therein so that the discis rotatable in the disc storage portion and that the first side of thedisc is exposed. The disc storage portion also has a disc window throughwhich the disc is inserted or removed into/from the disc storageportion. The chucking opening is formed on the bottom of the discstorage portion so as to get the disc chucked externally. The headopening is also formed on the bottom of the disc storage portion so asto allow a head, which reads and/or writes a signal from/on the secondside of the disc, to access the second side of the disc. The pair ofshutters is supported, and movable with respect to the cartridge body,between the second side of the disc and the bottom of the disc storageportion so as to expose or cover the chucking and head openings. Thedisc holding portions are provided for the shutters, press the discagainst the shutters, and hold the disc thereon while the chucking andhead openings are covered with the shutters. The stopper member issecured to the cartridge body so as to be movable between a state ofprotruding into the disc window and a state of not protruding into thedisc window.

In one embodiment, the stopper member is movable on a plane that isparallel to the upper surface of the cartridge body. The stopper membermay be rotatable on the upper surface of the cartridge body.

Yet another disc cartridge according to the present invention includes acartridge body, a pair of shutters, a number of disc holding portionsand a disc receiving portion. The cartridge body includes a disc storageportion, a chucking opening and a head opening. The disc storage portionstores a disc, having first and second sides, therein so that the discis rotatable in the disc storage portion and that the first side of thedisc is exposed. The chucking opening is formed on the bottom of thedisc storage portion so as to get the disc chucked externally. The headopening is also formed on the bottom of the disc storage portion so asto allow a head, which reads and/or writes a signal from/on the secondside of the disc, to access the second side of the disc. The pair ofshutters is supported, and movable with respect to the cartridge body,between the second side of the disc and the bottom of the disc storageportion so as to expose or cover the chucking and head openings. Thedisc holding portions are provided for the shutters, press the discagainst the shutters, and hold the disc thereon while the chucking andhead openings are covered with the shutters. The disc receiving portionis provided along the inner circumference of an inner lower surface ofthe disc storage portion so as to contact with an outer edge portion ofthe second side of the disc that is being held while the shutters areclosed.

In one embodiment, at least a part of the disc receiving portion isparallel to the inner lower surface of the disc storage portion andcontacts with the other side of the disc. The disc receiving portion maybe a taper that is provided between an inner side surface and the innerlower surface of the disc storage portion. While the shutters are closedand the disc is held, the outer edge of the disc may be in contact withthe disc receiving portion.

Yet another disc cartridge according to the present invention includes acartridge body, a pair of shutters and a number of disc holdingportions. The cartridge body includes a disc storage portion, a chuckingopening and a head opening. The disc storage portion stores a disc,having first and second sides, therein so that the disc is rotatable inthe disc storage portion and that the first side of the disc is exposed.The chucking opening is formed on the bottom of the disc storage portionso as to get the disc chucked externally. The head opening is alsoformed on the bottom of the disc storage portion so as to allow a head,which reads and/or writes a signal from/on the second side of the disc,to access the second side of the disc. The pair of shutters issupported, and movable with respect to the cartridge body, between thesecond side of the disc and the bottom of the disc storage portion so asto expose or cover the chucking and head openings. The disc holdingportions are provided for the shutters, press the disc against theshutters, and hold the disc thereon while the chucking and head openingsare covered with the shutters. An inner lower surface of the discstorage portion includes first regions, through which respective bottomsof the disc holding portions pass while the shutters are going to beopened or closed. The first regions are recessed.

Yet another disc cartridge according to the present invention includes acartridge body, a pair of shutters and a number of disc holdingportions. The cartridge body includes a disc storage portion, a chuckingopening and a head opening. The disc storage portion stores a disc,having first and second sides, therein so that the disc is rotatable inthe disc storage portion and that the first side of the disc is exposed.The chucking opening is formed on the bottom of the disc storage portionso as to get the disc chucked externally. The head opening is alsoformed on the bottom of the disc storage portion so as to allow a head,which reads and/or writes a signal from/on the second side of the disc,to access the second side of the disc. The pair of shutters issupported, and movable with respect to the cartridge body, between thesecond side of the disc and the bottom of the disc storage portion so asto expose or cover the chucking and head openings. The disc holdingportions are provided for the shutters, press the disc against theshutters, and hold the disc thereon while the chucking and head openingsare covered with the shutters. An inner lower surface of the discstorage portion includes second regions that are located in the vicinityof the outer periphery of the shutters while the shutters are closed.The second regions are recessed.

Yet another disc cartridge according to the present invention includes acartridge body, a pair of shutters and a number of disc holdingportions. The cartridge body includes a disc storage portion, a chuckingopening and a head opening. The disc storage portion stores a disc,having first and second sides, therein so that the disc is rotatable inthe disc storage portion and that the first side of the disc is exposed.The chucking opening is formed on the bottom of the disc storage portionso as to get the disc chucked externally. The head opening is alsoformed on the bottom of the disc storage portion so as to allow a head,which reads and/or writes a signal from/on the second side of the disc,to access the second side of the disc. The pair of shutters issupported, and movable with respect to the cartridge body, between thesecond side of the disc and the bottom of the disc storage portion so asto expose or cover the chucking and head openings. The disc holdingportions are provided for the shutters, press the disc against theshutters, and hold the disc thereon while the chucking and head openingsare covered with the shutters. An inner lower surface of the discstorage portion includes third regions that are located around thechucking and head openings and/or near an inner side surface of the discstorage portion. The third regions are recessed.

Yet another disc cartridge according to the present invention includes acartridge body, a shutter, a number of disc holding portions and firstand second operating portions. The cartridge body includes a discstorage portion, a chucking opening and a head opening. The disc storageportion stores a disc, having first and second sides, therein so thatthe disc is rotatable in the disc storage portion and that the firstside of the disc is exposed. The chucking opening is formed on thebottom of the disc storage portion so as to get the disc chuckedexternally. The head opening is also formed on the bottom of the discstorage portion so as to allow a head, which reads and/or writes asignal from/on the second side of the disc, to access the second side ofthe disc. The shutter is supported, and movable with respect to thecartridge body, between the second side of the disc and the bottom ofthe disc storage portion so as to expose or cover the chucking and headopenings. The disc holding portions are provided for the shutter, pressthe disc against the shutter and hold the disc thereon while thechucking and head openings are covered with the shutter. The first andsecond operating portions are used to open and close the shutter.

In one embodiment, the first and second operating portions arerespectively provided for first and second side surfaces of thecartridge body. The first and second side surfaces may be adjacent toeach other. The first operating portion may be a protrusion that isconnected to the shutter, and the shutter may be opened or closed bysliding the first operating portion along a portion of the first sidesurface. Also, the second operating portion may be a rotational memberthat is engaged with the shutter. Then, the shutter may be opened orclosed by rotating the second operating portion. Alternatively, thesecond operating portion may also be a sliding link member that isengaged with the shutter. Then, the shutter may be opened or closed bysliding the second operating portion along the second side surface.

In one example, the second operating portion may also be a belt memberthat is connected to the shutter. Then, the shutter may be opened orclosed by sliding the second operating portion along the second sidesurface.

In one example, the disc cartridge includes a pair of shutters,including the shutter. The first and second operating portions may beconnected to, or engaged with, the pair of shutters, respectively.

Yet another disc cartridge according to the present invention includes acartridge body, a pair of shutters, a number of disc holding portionsand a rotation stopper member. The cartridge body includes a discstorage portion, a chucking opening and a head opening. The disc storageportion stores a disc, having first and second sides, therein so thatthe disc is rotatable in the disc storage portion and that the firstside of the disc is exposed. The chucking opening is formed on thebottom of the disc storage portion so as to get the disc chuckedexternally. The head opening is also formed on the bottom of the discstorage portion so as to allow a head, which reads and/or writes asignal from/on the second side of the disc, to access the second side ofthe disc. The pair of shutters is supported, and movable with respect tothe cartridge body, between the second side of the disc and the bottomof the disc storage portion so as to expose or cover the chucking andhead openings. The disc holding portions are provided for the shutters,press the disc against the shutters, and hold the disc thereon while thechucking and head openings are covered with the shutters. The rotationstopper member is provided for at least one of the disc holding portionsto prevent the disc from rotating while the shutters are closed.

In one example, the rotation stopper member is made of a material havinga large coefficient of friction and is provided for the at least one ofthe disc holding portions so as to contact with the disc while theshutters are closed.

In one example, the rotation stopper member is made of rubber.

Yet another disc cartridge according to the present invention includes acartridge body, a pair of shutters, a number of disc holding portionsand at least one stopper member. The cartridge body includes a discstorage portion, a chucking opening and a head opening. The disc storageportion has a disc window and stores a disc, having first and secondsides, therein so that the disc is rotatable in the disc storage portionand that the first side of the disc is exposed inside the disc discwindow. The chucking opening is formed on the bottom of the disc storageportion so as to get the disc chucked externally. The head opening isalso formed on the bottom of the disc storage portion so as to allow ahead, which reads and/or writes a signal from/on the second side of thedisc, to access the second side of the disc. The pair of shutters issupported, and movable with respect to the cartridge body, between thesecond side of the disc and the bottom of the disc storage portion so asto expose or cover the chucking and head openings. The disc holdingportions are provided for the shutters, press the disc against theshutters, and hold the disc thereon while the chucking and head openingsare covered with the shutters. The at least one stopper member isprovided for the cartridge body so as to protrude at least partiallyinto the disc window. The head opening reaches a side surface of thecartridge body. An operating portion for use to open and close theshutters is provided for the shutters and is located inside the headopening.

In one example, the shutters have first and second pairs of contactsurfaces, each pair contacting with each other. The first and secondpairs are not aligned with each other. The contact surfaces of each ofthe first and second pairs may be sloped, and overlap with each other,in a thickness direction of the disc. In the first pair of contactsurfaces, the contact surface of one of the two shutters may be locatedover the contact surface of the other shutter. In the second pair ofcontact surfaces on the other hand, the contact surface of the oneshutter may be located under the contact surface of the other shutter.While closed, the shutters may define a hole in a region correspondingto a center hole of the disc. Specifically, the hole defined by theshutters may have a diameter that is approximately equal to that of thecenter hole of the disc.

In one example, the disc holding portions are provided at two ends ofthe shutters, and each of the disc holding portions has a downwardlytapered slope. At least one of the disc holding portions may be providedso as to be movable toward the center of the disc.

In one example, each of the disc holding portions includes a firstportion with a first height and a second portion with a second heightthat is lower than the first height. An upper surface of the cartridgebody has a recessed portion to receive the top of the first portion ofeach of the disc holding portions that moves as the shutters are goingto be opened or closed. The recessed portion is thinner than anotherportion of the upper surface of the cartridge body under which thesecond portion of each of the disc holding portions moves.

As the shutters are going to be closed, the first portion may contactwith the disc earlier than the second portion.

In one example, the stopper member has a contact surface that contactswith the disc 100. A portion of the slope of at least one of the discholding portions is located over the contact surface of the stoppermember.

In one example, the shutters rotate on a pair of rotation shafts thatare provided for the disc cartridge body. The shutters may includeinterlocking portions that interlock with each other to open or closethe shutters. The disc cartridge may further include an elastic memberthat applies a force to the shutters to keep the shutters closed.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view illustrating an overall configuration for adisc cartridge according to a first embodiment of the present invention.

FIG. 2 is a perspective view of the disc cartridge shown in FIG. 1 asviewed from below it.

FIG. 3 is an exploded perspective view illustrating an exploded state ofthe disc cartridge shown in FIG. 1.

FIG. 4 is a cross-sectional view illustrating a disc holding member anda surrounding portion of the disc cartridge shown in FIG. 1.

FIG. 5 is a cross-sectional view illustrating another disc holdingmember and a surrounding portion of the disc cartridge shown in FIG. 1.

FIG. 6 is a perspective view illustrating a state of the disc cartridgeshown in FIG. 1 in which its shutter is opened and positioning pins havebeen inserted.

FIG. 7 is a cross-sectional view illustrating the disc holding memberand its surrounding portion shown in FIG. 6.

FIG. 8 is a perspective view illustrating the disc holding member andits surrounding portion shown in FIG. 6.

FIG. 9 is a plan view illustrating an overall configuration for a disccartridge according to a second embodiment of the present invention.

FIG. 10 is a plan view illustrating a state of the disc cartridge shownin FIG. 9 in which the disc has been released.

FIG. 11 is a plan view illustrating an overall configuration for a disccartridge according to a third embodiment of the present invention.

FIG. 12 is a plan view illustrating a state of the disc cartridge shownin FIG. 11 in which the disc has been released.

FIG. 13 is a plan view illustrating an overall configuration for a disccartridge according to a fourth embodiment of the present invention.

FIG. 14 is a plan view illustrating a state of the disc cartridge shownin FIG. 13 in which the disc has been released.

FIG. 15 is a plan view illustrating an overall configuration for a disccartridge according to a fifth embodiment of the present invention in astate where its shutter is closed.

FIG. 16 is a cross-sectional view of a disc holding member of the disccartridge shown in FIG. 15.

FIG. 17 is a plan view illustrating an overall configuration for thedisc cartridge shown in FIG. 15 in a state where its shutter is opened.

FIG. 18 is a cross-sectional view of the disc holding member of the disccartridge shown in FIG. 17.

FIG. 19 is a plan view illustrating an overall configuration for a disccartridge according to a sixth embodiment of the present invention in astate where its shutter is closed.

FIG. 20 is a plan view illustrating an overall configuration for thedisc cartridge shown in FIG. 19 in a state where its shutter is opened.

FIG. 21 is a plan view illustrating an overall configuration for a disccartridge according to a seventh embodiment of the present invention ina state where its shutter is closed.

FIG. 22 is a plan view illustrating an overall configuration for thedisc cartridge shown in FIG. 21 in a state where its shutter is opened.

FIG. 23 is a perspective view illustrating an overall configuration fora disc cartridge according to an eighth embodiment.

FIG. 24 is an exploded perspective view illustrating an exploded stateof the disc cartridge shown in FIG. 23.

FIG. 25 is a perspective view illustrating a state of the disc cartridgeshown in FIG. 23 in which its shutters are closed with its cartridgeupper shell and the disc removed.

FIG. 26 is a perspective view illustrating a state of the disc cartridgeshown in FIG. 23 in which its shutters are opened with its cartridgeupper shell and the disc removed.

FIG. 27 is a perspective view illustrating a state of the disc cartridgeshown in FIG. 23 in which its shutters are closed with the disc removed.

FIG. 28 is a perspective view illustrating a state of the disc cartridgeshown in FIG. 23 in which its shutters are opened with the disc removed.

FIG. 29 is a partial cross-sectional view illustrating a cross sectionof the disc cartridge shown in FIG. 23 that passes the center of thedisc.

FIG. 30 is a cross-sectional view illustrating a portion of the shutterof the disc cartridge shown in FIG. 23.

FIG. 31 is a partial plan view illustrating an operating portion and itssurrounding portion of the disc cartridge shown in FIG. 23.

FIG. 32 is a perspective view illustrating a stopper member of the disccartridge shown in FIG. 23.

FIG. 33 is a front view of the disc cartridge shown in FIG. 23 as viewedfrom a direction in which the cartridge is inserted into a drive.

FIG. 34 is a perspective view illustrating an overall configuration fora disc cartridge according to a ninth embodiment of the presentinvention.

FIG. 35 is an exploded perspective view illustrating an exploded stateof the disc cartridge shown in FIG. 34.

FIG. 36 is a perspective view illustrating a state of the disc cartridgeshown in FIG. 34 in which its shutters are closed with the disc removed.

FIG. 37 is a perspective view illustrating a state of the disc cartridgeshown in FIG. 34 in which its shutters are opened with the disc removed.

FIG. 38 is a partial cross-sectional view illustrating a cross sectionof the disc cartridge shown in FIG. 34 that passes the center of thedisc to show a state where its shutters are closed.

FIG. 39 is a partial cross-sectional view illustrating a cross sectionof the disc cartridge shown in FIG. 34 that passes the center of thedisc to show a state where its shutters are opened.

FIG. 40 is a cross-sectional view illustrating a disc outer peripheralcross section of the disc cartridge shown in FIG. 34 that passes thecenter of the disc to show a state where its shutters are closed.

FIG. 41 is a cross-sectional view illustrating a disc outer peripheralcross section of the disc cartridge shown in FIG. 34 that passes thecenter of the disc to show a state where its shutters are opened.

FIG. 42 is a perspective view illustrating an overall configuration fora disc cartridge according to a tenth embodiment of the presentinvention.

FIG. 43 is an exploded perspective view illustrating an exploded stateof the disc cartridge shown in FIG. 42.

FIG. 44 is a perspective view illustrating a state of the disc cartridgeshown in FIG. 42 in which its shutters are closed with the disc removed.

FIG. 45 is a perspective view illustrating a state of the disc cartridgeshown in FIG. 42 in which its shutters are opened with the disc removed.

FIG. 46 is a partial cross-sectional view illustrating a cross sectionof the disc cartridge shown in FIG. 42 that passes the center of thedisc to show a state where its shutters are closed.

FIG. 47 is a partial cross-sectional view illustrating a cross sectionof the disc cartridge shown in FIG. 42 that passes the center of thedisc to show a state where its shutters are opened.

FIG. 48 is a cross-sectional view illustrating a disc outer peripheralcross section of the disc cartridge shown in FIG. 42 that passes thecenter of the disc to show a state where its shutters are closed.

FIG. 49 is a cross-sectional view illustrating a disc outer peripheralcross section of the disc cartridge shown in FIG. 42 that passes thecenter of the disc to show a state where its shutters are opened.

FIG. 50 is a perspective view illustrating an overall configuration fora disc cartridge according to an eleventh embodiment of the presentinvention.

FIG. 51 is an exploded perspective view illustrating an exploded stateof the disc cartridge shown in FIG. 50.

FIG. 52 is a perspective view illustrating a state of the disc cartridgeshown in FIG. 50 in which its shutters are closed with the disc removed.

FIG. 53 is a perspective view illustrating a state of the disc cartridgeshown in FIG. 50 in which its shutters are opened with the disc removed.

FIG. 54 is a partial cross-sectional view illustrating a cross sectionof the disc cartridge shown in FIG. 50 that passes the center of thedisc to show a state where its shutters are closed.

FIG. 55 is a partial cross-sectional view illustrating a cross sectionof the disc cartridge shown in FIG. 50 that passes the center of thedisc to show a state where its shutters are opened.

FIG. 56 is a cross-sectional view illustrating a portion of the shutterof the disc cartridge shown in FIG. 50.

FIG. 57 is a partial plan view illustrating an operating portion and itssurrounding portion of the disc cartridge shown in FIG. 50.

FIG. 58 is a perspective view illustrating a state of a disc cartridgeaccording to a twelfth embodiment of the present invention in which itsshutters are closed with the disc removed.

FIG. 59 is a partial cross-sectional view illustrating a cross sectionof the disc cartridge shown in FIG. 58 that passes the center of thedisc to show a state where its shutters are closed.

FIG. 60 is a perspective view illustrating a state of the disc cartridgeshown in FIG. 58 in which its shutters are opened with the disc removed.

FIG. 61 is a partial cross-sectional view illustrating a cross sectionof the disc cartridge shown in FIG. 58 that passes the center of thedisc to show a state where its shutters are opened.

FIG. 62 is a perspective view illustrating a modified example of thedisc cartridge shown in FIG. 58 to show a state where its shutters areclosed with the disc removed.

FIG. 63 is a perspective view illustrating a state of the disc cartridgeshown in FIG. 61 in which its shutters are opened with the disc removed.

FIG. 64 is a perspective view illustrating an overall configuration fora disc cartridge according to a thirteenth embodiment of the presentinvention.

FIG. 65 is an exploded perspective view illustrating an exploded stateof the disc cartridge shown in FIG. 64.

FIG. 66 is a schematic plan view illustrating a state of the disccartridge shown in FIG. 64 in which its shutters are closed.

FIG. 67 is a schematic plan view illustrating a state of the disccartridge shown in FIG. 64 in which its shutters are opened.

FIG. 68 is a detailed perspective view of a shutter locking portion.

FIG. 69 is a detailed cross-sectional view of a disc holding portion ofthe shutter.

FIG. 70 is a cross-sectional view illustrating the shapes of a pair ofcontact surfaces of the two shutters.

FIG. 71 is a cross-sectional view illustrating the shapes of anotherpair of contact surfaces of the two shutters.

FIG. 72 is a perspective view illustrating an overall configuration fora disc cartridge according to a fourteenth embodiment of the presentinvention.

FIG. 73 is a perspective view illustrating the shutters of the disccartridge shown in FIG. 72.

FIG. 74 is an enlarged perspective view illustrating the disc holdingportions and their surrounding members of the disc cartridge shown inFIG. 72.

FIG. 75 is an enlarged perspective view illustrating the disc holdingportion and its surrounding portion of the disc cartridge shown in FIG.72.

FIG. 76 is an enlarged cross-sectional view illustrating the discholding portion and its surrounding members of the disc cartridge shownin FIG. 72.

FIG. 77 is a schematic plan view illustrating a state of the disccartridge shown in FIG. 72 in which its shutters are closed.

FIG. 78 is a schematic plan view illustrating a state of the disccartridge shown in FIG. 72 in which its shutters are opened.

FIG. 79 is a cross-sectional view taken along the line B—B shown in FIG.78.

FIG. 80 is a cross-sectional view taken along the line C—C shown in FIG.78.

FIG. 81 is a cross-sectional view taken along the line A—A shown in FIG.77.

FIG. 82 is a cross-sectional view illustrating a modified example of thedisc receiving portion.

FIG. 83 is an exploded perspective view illustrating an exploded stateof a disc cartridge according to a fifteenth embodiment of the presentinvention.

FIG. 84 is a schematic plan view illustrating a state of the disccartridge shown in FIG. 83 in which its shutters are closed.

FIG. 85 is a schematic plan view illustrating a state of the disccartridge shown in FIG. 83 in which its shutters are opened.

FIG. 86 is a cross-sectional view taken along the line D—D shown in FIG.84.

FIG. 87 is a cross-sectional view taken along the line E—E shown in FIG.85.

FIG. 88 is a perspective view illustrating an overall configuration fora disc cartridge according to a sixteenth embodiment of the presentinvention.

FIG. 89 is an exploded perspective view illustrating an exploded stateof the disc cartridge shown in FIG. 88.

FIG. 90 is a schematic plan view illustrating a state of the disccartridge shown in FIG. 88 in which its shutters are closed.

FIG. 91 is a schematic plan view illustrating a state of the disccartridge shown in FIG. 88 in which its shutters are opened.

FIG. 92 is a schematic plan view illustrating a modified example of thedisc cartridge shown in FIG. 88 to show a state where the shutters ofthe disc cartridge are closed.

FIG. 93 is a schematic plan view illustrating a state of the disccartridge shown in FIG. 92 in which its shutters are opened.

FIG. 94 is a perspective view illustrating an overall configuration fora disc cartridge according to a seventeenth embodiment of the presentinvention.

FIG. 95 is an exploded perspective view illustrating an exploded stateof the disc cartridge shown in FIG. 94.

FIG. 96 is a schematic plan view illustrating a state of the disccartridge shown in FIG. 94 in which its shutters are closed.

FIG. 97 is a schematic plan view illustrating a state of the disccartridge shown in FIG. 94 in which its shutters are opened.

FIG. 98 is a perspective view illustrating an overall configuration fora disc cartridge according to an eighteenth embodiment of the presentinvention.

FIG. 99 is an exploded perspective view illustrating an exploded stateof the disc cartridge shown in FIG. 98.

FIG. 100 is a schematic plan view illustrating a state of the disccartridge shown in FIG. 98 in which its shutters are closed.

FIG. 101 is a schematic plan view illustrating a state of the disccartridge shown in FIG. 98 in which its shutters are opened.

FIG. 102 is an exploded perspective view illustrating an exploded stateof a disc cartridge according to a nineteenth embodiment of the presentinvention.

FIG. 103 is an enlarged cross-sectional view illustrating a disc holdingportion and its surrounding members of the disc cartridge shown in FIG.102.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Embodiment 1

Hereinafter, a disc cartridge 301 according to a first embodiment of thepresent invention will be described with reference to FIGS. 1, 2 and 3.FIG. 1 is a perspective view illustrating an overall configuration ofthe disc cartridge 301, including a disc 100 stored, as viewed fromabove the cartridge 301. FIG. 2 is a perspective view of the disccartridge 301 as viewed from below the cartridge 301. FIG. 3 is anexploded perspective view illustrating respective parts of the disccartridge 301.

The disc 100 includes first and second sides. The first side of the disc100, on which its label, for example, is normally printed, isillustrated in FIG. 1, while the second side of the disc 100, i.e., thesignal recording side 100A, is illustrated as the back surface in FIG.3.

As shown in FIG. 1, the disc cartridge 301 includes a cartridge lowershell 11, a cartridge upper shell 12, disc holding members 13, 14 and ashutter 21.

As shown in FIG. 3, the cartridge lower shell 11 includes a chuckingopening 11 c and a head opening 11 h. The chucking opening 11 c isprovided to allow a chucking member (e.g., a spindle motor for rotatingthe disc 100) to enter the disc cartridge 301 externally. The headopening 11 h is provided to allow a head, which reads and/or writes asignal from/on the signal recording side 100A of the disc 100, to enterthe disc cartridge 301 and access the signal recording side 100A. Thecartridge lower shell 11 also includes two positioning holes 11 w, whichengage with cartridge positioning pins 210 of a disc drive, therebydefining the position of the disc cartridge 301 with respect to the discdrive. The cartridge lower shell 11 faces the signal recording side 100Aof the disc 100.

The cartridge upper shell 12 includes a circular disc window 12 w,through which the disc 100 can be introduced and removed into/from thedisc cartridge 301 and which expands over the entire projection area ofthe disc 100 to expose the upper surface of the disc 100. The cartridgeupper and lower shells 12 and 11 are adhered or welded together at theirouter periphery, thereby forming a cartridge body 10.

A disc storage portion 10 d for storing the disc 100 therein (seeFIG. 1) is defined by a first inner surface 11 u of the cartridge lowershell 11 and a second inner surface 12 i of the cartridge upper shell12. The first inner surface 11 u is opposed to the signal recording side100A of the disc 100, while the second inner surface 12 i has asubstantially cylindrical shape and defines the disc window 12 w inside.That is to say, the first inner surface 11 u becomes the bottom of thedisc storage portion 10 d. The first inner surface 11 u of the cartridgelower shell 11 is provided with a protective layer 11 p for the purposeof preventing the disc 100 from getting scratched or any dust fromreaching the signal recording side 100A.

The protective layer 11 p may be appropriately selected from the groupconsisting of an anti-scratching nonwoven fabric, a dustproof nonwovenfabric, an anti-scratching coating layer and a dustproof coating layer.In this embodiment, a sheet of a dustproof nonwoven fabric is adhered orultrasonic welded as the protective layer 11 p.

In the disc storage portion 10 d, a gap, which is wide enough to allowthe disc 100 to rotate freely, is provided between the second innersurface 12 i and the disc 100. Also, the top of the disc storage portion10 d is the disc window 12 w so that the disc 100 stored in the discstorage portion 10 d has one side thereof exposed inside the disc window12 w.

As shown in FIG. 3, the disc cartridge 301 includes two disc holdingmembers 13 of the same shape. Each of the disc holding members 13includes a pair of elastic portions 13 d and a hole portion 13 w thatruns obliquely through the disc holding member 13. When the elasticportions 13 d of the disc holding members 13 are sandwiched between thecartridge upper and lower shells 12 and 11, an elastic force is appliedto the respective ends of the disc holding members 13 in the directionindicated by the arrows 13B in FIG. 3. As a result, the disc 100 ispressed against the first inner surface 11 u. Also, these two discholding members 13 are disposed so that the hole portions 13 w thereofare located substantially over the positioning holes 11 w.

The disc holding member 14 includes a rotation shaft 14 s and twoelastic portions 14 d. The disc holding member 14 is secured to thecartridge body 10 so as to rotate on the rotation shaft 14 s. When theelastic portions 14 d are sandwiched between the cartridge upper andlower shells 12 and 11, an elastic force is applied to the respectiveends of the disc holding member 14 in the direction indicated by thearrow 14B. As a result, the disc 100 is pressed against the first innersurface 11 u.

The shutter 21 is externally fitted with the cartridge lower shell 11 soas to face the signal recording side 100A of the disc 100. As shown inFIGS. 1 and 2, when the shutter is moved in the direction indicated bythe arrow 21A or 21B, the chucking opening 11 c and the head opening 11h are exposed or covered. A shutter spring 31 is extended between theshutter 21 and the cartridge body 10 to apply an elastic force to theshutter 21 in such a direction as to close the shutter 21.

As shown in FIG. 2, a label plane or concave portion 10 f, on which thecontents that have been written on the disc 100 being stored can benoted down, is provided on the surface of the cartridge body 10 (i.e.,the cartridge lower shell 11). Also, a pair of concave portions 10 c,provided on the right- and left-hand sides of the cartridge body 10, maybe used as either pull-in notches or positioning recesses when the disccartridge 301 is pulled in and loaded into a disk drive or when the disccartridge 301 is stored in a changer. Another concave portion 10 g,provided on just one side, has such a shape as to prevent erroneousinsertion of the disc cartridge 301. That is to say, this concaveportion 10 g is just fitted with a convex portion provided for the discdrive only when the disc cartridge 301 is inserted in the correctdirection. Suppose the disc cartridge 301 is being inserted into thedisc drive upside down or the wrong way round by mistake. In that case,these concave and convex portions are never fitted with each other andthe disc cartridge 301 cannot be inserted thereto correctly. In thismanner, the erroneous insertion can be prevented.

Next, it will be described in further detail with reference to FIGS. 4and 5 how the disc holding members 13 and 14 hold the disc 100 thereon.FIG. 4 is a cross-sectional view of the disc holding member 13 in astate where the disc 100 has been mounted thereon as shown in FIGS. 1through 3, while FIG. 5 is a cross-sectional view of the disc holdingmember 14 in the state where the disc 100 has been mounted thereon.FIGS. 4 and 5 are both taken in a disc radial direction.

As shown in FIGS. 4 and 5, the disc holding members 13 and 14 includeslopes 13′ and 14′, which overhang a portion of the projection area ofthe disc 100 (i.e., over the outer periphery of the disc 100), at therespective ends thereof. An elastic force is applied from the elasticportions 13 d or 14 d to the disc holding member 13 or 14 in thedirection indicated by the arrow 13B or 14B. In that situation, theslope 13′ or 14′ contacts with the outer edge 100 c of the disc 100,thereby gripping the disc 100 thereon and pressing the disc 100 in athickness direction 100 t thereof. As a result, the signal recordingside 100A is brought into plane contact with the sheet 11 p. In thismanner, the disc 100 is held and fixed inside the cartridge body 10. Inthis state, the outer periphery of the signal recording side 100A of thedisc 100 keeps a close contact with the sheet 11 p. Thus, no dust willbe deposited on the signal recording side 100A.

Next, it will be described in detail with reference to FIGS. 6, 7 and 8how the disc 100 is released from the disc holding members 13 and 14.

FIG. 6 is a perspective view illustrating the disc cartridge with thecartridge upper shell 12 and the disc 100 removed therefrom. As shown inFIG. 6, the shutter 21 has its L-shaped portion 21 s pressed by ashutter opening mechanism (not shown) of the disc drive in the directionindicated by the arrow 21A. As a result, the chucking opening 11 c andthe head opening 11 h are now exposed. Also, the pair of cartridgepositioning pins 210 of the disc drive is engaged with the positioningholes 11 w of the cartridge body 10.

FIG. 7 is a cross-sectional view of the disc holding member 13 in thestate shown in FIG. 6 and is taken in a disc radial direction. FIG. 8 isan enlarged view illustrating the main parts, or the disc holding member14 and the shutter 21 in the state shown in FIG. 6.

As shown in FIG. 7, when the cartridge positioning pin 210 of the discdrive is inserted into the positioning hole 11 w, the cartridgepositioning pin 210 engages with the obliquely running hole portion 13 wof the disc holding member 13. As a result, the disc holding member 13is lifted in the direction 13A, and the disc 100 is released from thegrip of the slope 13′ and is now freely rotatable. At this point intime, the rim 13 e at the end of the disc holding member 13 stilloverhangs a portion of the projection area of the disc (i.e., the outerperiphery thereof). Accordingly, even if the disc 100 is released in adisk drive that is so constructed as to mount the disc 100 vertically,the disc 100 will not drop down from the disc cartridge 301.

On the other hand, when the shutter 21 is opened, a guide rib 21 xprovided on the shutter 21 enters a concave portion 14 w of the discholding member 14, thereby lifting the ceiling of the concave portion 14w as shown in FIG. 8. As a result, the disc holding member 14 is liftedto the direction 14A and the disc 100 is released from the grip of theslope 14′ and becomes freely rotatable. At this point in time, the rim14 e at the end of the disc holding member 14 still overhangs a portionof the projection area of the disc (i.e., the outer periphery thereof).Accordingly, even if the disc is released in a disk drive that is soconstructed as to mount the disc 100 vertically, the disc 100 will notdrop down from the disc cartridge 301.

Also, to remove the disc intentionally, the operator must release thedisc from the three disc holding members 13 and 14 at the same time.Accordingly, it is possible to prevent the operator from removing thedisc accidentally.

In this embodiment, the end 21 r of the shutter 21, which is opposed tothe disc 100, may be provided with a brush or a dust cleaning member asshown in FIG. 2 so that dust is removed from the signal recording side100A of the disc 100 every time the shutter 21 is opened and closed.Optionally, the disc cartridge 301 may further include a lockingmechanism for fixing and supporting the disc holding members onto thecartridge body 10 when the disc is held.

Embodiment 2

Hereinafter, a disc cartridge 302 according to a second embodiment ofthe present invention will be described with reference to FIGS. 9 and10. Specifically, FIG. 9 is plan view illustrating an overallconfiguration for the disc cartridge 302 in which the disc 100 is held.FIG. 10 is a plan view illustrating an overall configuration for thedisc cartridge 302 in which the disc 100 has been released. In FIGS. 9and 10, each member equivalent to the counterpart of the firstembodiment described above is identified by the same reference numeraland the description thereof will be omitted herein.

The disc cartridge 302 is different from the disc cartridge 301 of thefirst embodiment in the disc holding members. Specifically, the disccartridge 302 includes two pairs of disc holding members 15 and 16,which slide in the direction indicated by the arrow 15A or 15B, as shownin FIG. 9.

Each of the disc holding members 15 includes an elastic portion 15 d,which applies an elastic force to the disc holding member 15 in thedirection indicated by the arrow 15B. Just like the disc holding members13 and 14 of the first embodiment, a slope 15′ provided at the endthereof holds and fixes the disc 100 onto the cartridge body 10.

Each of the disc holding members 16 includes a rotation shaft 16 c. Thatis to say, the disc holding member 16 is provided for the cartridge body10 so as to rotate on its rotation shaft 16 c. Just like the discholding members 13 and 14 of the first embodiment, a slope 16′ providedat the end of each disc holding member 16 holds and fixes the disc 100onto the cartridge body 10. Each of the disc holding members 15 furtherincludes a coupling pin 15 p, which is engaged and interlocked with agroove 16 g provided for its associated disc holding member 16.

When the two cartridge positioning pins 210 of the disc drive areengaged with the positioning holes 11 w of the cartridge body 10,respective protrusions 15 s of the disc holding members 15 are pushed bythe positioning pins 210 as shown in FIG. 10. As a result, the discholding members 15 are moved in the direction indicated by the arrow 15Aand the disc 100 is released from the grip of the slopes 15′. In themeantime, as the disc holding members 15 are moved, the disc holdingmembers 16 are rotated to the direction indicated by the arrow 16A.Consequently, the disc 100 is also released from the grip of the slopes16′.

Embodiment 3

Hereinafter, a disc cartridge 303 according to a third embodiment of thepresent invention will be described with reference to FIGS. 11 and 12.Specifically, FIG. 11 is plan view illustrating an overall configurationfor the disc cartridge 303 in which the disc 100 is held. FIG. 12 is aplan view illustrating an overall configuration for the disc cartridge303 in which the disc 100 has been released. In FIGS. 11 and 12, eachmember equivalent to the counterpart of the first embodiment isidentified by the same reference numeral and the description thereofwill be omitted herein.

The disc cartridge 303 is different from the disc cartridge 301 of thefirst embodiment in the disc holding members. Specifically, the disccartridge 303 includes two pairs of disc holding members 17 and 18, towhich an elastic force is applied in the directions indicated by thearrows 17B and 18B, respectively, as shown in FIG. 11. These discholding members 17 and 18 have been molded together with the cartridgebody 10 so as to form integral parts of the cartridge body 10.

Each of the disc holding members 17 includes an elastic portion 17 d,which applies an elastic force to the disc holding member 17 in thedirection indicated by the arrow 17B. Just like the disc holding members13 and 14 of the first embodiment, a slope 17′ provided at the end ofeach disc holding member 17 holds and fixes the disc 100 onto thecartridge body 10.

Each of the disc holding members 18 also includes an elastic portion 18d, which applies an elastic force to the disc holding member 18 in thedirection indicated by the arrow 18B. A slope 18′ provided at the end ofeach disc holding member 18 also holds and fixes the disc 100 onto thecartridge body 10.

When this disc cartridge 303 is inserted into a disc drive 200, a pairof disc releasing pins 217, provided for the disc drive 200, pressesprotrusions 17 s of the disc holding members 17. As a result, the disc100 is released from the disc holding members 17 as shown in FIG. 12. Atthe same time, another pair of disc releasing pins 218, also providedfor the disc drive 200, contacts with the side surfaces 18 s of the discholding members 18. Consequently, the disc 100 is also released from thedisc holding members 18.

Embodiment 4

Hereinafter, a disc cartridge 304 according to a fourth embodiment ofthe present invention will be described with reference to FIGS. 13 and14. Specifically, FIG. 13 is plan view illustrating an overallconfiguration for the disc cartridge 304 in which the disc 100 is held.FIG. 14 is a plan view illustrating an overall configuration for thedisc cartridge 304 in which the disc 100 has been released. In FIGS. 13and 14, each member equivalent to the counterpart of the firstembodiment is identified by the same reference numeral and thedescription thereof will be omitted herein.

The disc cartridge 304 is different from the disc cartridge 301 of thefirst embodiment in the disc holding member. Specifically, the disccartridge 304 includes a ringlike disc holding member 19.

As shown in FIG. 13, the disc holding member 19 is a ringlike elasticmember, which is made of rubber, for example, and which can change itsshape freely. When no force is externally applied thereto, the discholding member 19 has an ellipsoidal shape. However, by applying anexternal force thereto, the disc holding member 19 may be deformed intoa substantially completely round shape. When the disc holding member 19is deformed into a substantially completely round shape, the insidediameter thereof is greater than the diameter of the disc 100.

As shown in FIG. 13, the ellipsoidal disc holding member 19 is incontact with the disc 100 at multiple points, thereby holding and fixingthe disc 100 onto the cartridge body 10. However, when this disccartridge 304 is inserted into a disc drive 200, a pair of convexportions 219, provided for the disc drive 200, presses the major axisportion of the ringlike disc holding member 19, thereby deforming thedisc holding member 19 as shown in FIG. 14. As a result, the discholding member 19 is deformed into an approximately completely roundshape and is no longer in contact with the disc 100. That is to say, thedisc 100 is released from the disc holding member 19.

To release the disc 100 from the disc holding member 19, the force thatdeforms the disc holding member 19 may also be applied from the convexportion of the disc drive, which engages with the concave portion 10 g(see FIG. 2) provided for preventing the erroneous insertion, to thedisc holding member 19. Alternatively, that force may also be appliedfrom a pair of convex portions of the disc drive, which engages with theconcave portions 10 c (see FIG. 2) provided on the right- and left-handsides of the disc cartridge 1 for pulling in the disc cartridge 304, tothe disc holding member 19.

Embodiment 5

Hereinafter, a fifth embodiment of the present invention will bedescribed with reference to FIGS. 15 through 18. FIGS. 15 and 17 areplan views illustrating the structure of a portion of a disc cartridge305 according to this embodiment from which the cartridge upper shellhas been removed. Specifically, FIG. 15 illustrates a state where theshutter 21 covers the openings 11 h and 11 c, while FIG. 17 illustratesa state where the shutter 21 exposes the openings 11 h and 11 c. FIGS.16 and 18 illustrate states of a disc holding portion 43 when theshutter 21 is closed and when the shutter 21 is opened, respectively.

In this embodiment, each member equivalent to the counterpart of thedisc cartridge of the first embodiment is identified by the samereference numeral.

The disc cartridge of this embodiment is characterized in that the discholding and releasing operations by disc holding members 43 aresynchronized with the opening and closing operations by the shutter 21by way of a disc holding/interlocking member 44.

The disc holding/interlocking member 44 is provided over the first innersurface 11 u of the cartridge lower shell 11 so as to rotate and slidearound the chucking opening 11 c of the cartridge lower shell 11 asindicated by the arrow 44A in FIGS. 15 and 17. The discholding/interlocking member 44 has a fan shape, or in the shape of apartially notched ring that has an inside diameter equal to the diameterof the chucking opening 11 c.

The disc holding/interlocking member 44 includes an engaging pin 47 thatextends toward the cartridge lower shell 11 (i.e., in the directiongoing into the paper of FIGS. 15 and 17). The cartridge lower shell 11and the shutter 21 are respectively provided with guide grooves 11 m and21 m that both engage with this engaging pin 47. Also, multipleprotrusions 45, which extend outward and toward the cartridge uppershell (i.e., in the direction coming out of the paper of FIGS. 15 and17), are provided on the outer periphery of the discholding/interlocking member 44. Furthermore, the upper surface of thedisc holding/interlocking member 44 is covered with a nonwoven fabric ora coating to prevent the disc 100 from getting scratched or dust frombeing deposited on the signal recording side thereof.

A number of disc holding members 43 are disposed at predeterminedintervals on respective regions of the cartridge lower shell 11 so as tohold the outer edge portion of the disc thereon when the disc is storedin the disc cartridge. In FIGS. 15 and 17, three disc holding members 43are provided. Alternatively, two, four or more disc holding members 43may also be provided. In any case, each of those disc holding members 43is secured to the cartridge lower shell 11 so as to rotate on therotation shaft 43A thereof.

As shown in FIG. 16, the disc holding member 43 is located at such aposition as to partially overlap with the outer periphery and itssurrounding portion of the disc holding/interlocking member 44. Also, amechanism (not shown in FIG. 16) such as the elastic portion 14 d shownin FIG. 5, for example, presses the disc holding member 43 in thedirection 43B (i.e., toward the cartridge lower shell 11). Accordingly,while contacting with the edge of the disc 100, the slope 43′ of thedisc holding member 43 not only presses the disc 100 in the direction43B so that the disc 100 is brought into contact with the discholding/interlocking member 44 but also holds the disc 100 thereon.

As shown in FIG. 15, when the disc cartridge holding the disc (notshown) thereon is inserted into a disc drive 200 in the directionindicated by the arrow 1A, a shutter opening/closing lever (not shown),provided for the disc drive 200, moves the shutter 21 in the direction21A, thereby opening the shutter 21. When the shutter 21 starts to movein the direction 21A, a force is also applied in the arrowed direction21A to the engaging pin 47 of the disc holding/interlocking member 44that is inserted into the guide groove 21 m of the shutter 21. As aresult, the engaging pin 47 is moved along the guide groove 11 m of thecartridge lower shell 11, and the disc holding/interlocking member 44starts to rotate around the chucking opening 11 c as indicated by thearrow 44A. The guide groove 11 m preferably extends approximately in thedirection in which the shutter 21 is moved so that the discholding/interlocking member 44 moves synchronously with the shutter 21.

When the shutter 21 is completely open, the protrusions 45 on the outerperiphery of the disc holding/interlocking member 44 are located underthe disc holding members 43 as shown in FIG. 17. Then, as shown in FIG.18, the disc holding members 43 are pushed up by the protrusions 45 andthe slopes 43′ of the disc holding members 43 separate themselves fromthe outer edge of the disc 100. As a result, the force 43B that haspressed the disc 100 vertically to the disc plane is removed and thedisc 100 is released to be freely rotatable. At this point in time, therim 43 e at the end of the disc holding member 43 still overhangs aportion of the projection area of the disc 100 (i.e., the outerperiphery thereof). Accordingly, even if the disc 100 is released in adisc drive that is supposed to mount the disc thereon vertically, thedisc will not drop down from the cartridge.

In the disc cartridge 305 of this embodiment, the disc can be releasedeven if the disc cartridge is not inserted into the disc drive 200. Forexample, if the shutter 21 is opened manually, the disc holding members43 will release the disc 100 synchronously with the movement of theshutter 21. Thus, the user can remove the existing disc from thecartridge and insert another disc thereto intentionally.

Embodiment 6

Hereinafter, a sixth embodiment of the present invention will bedescribed. FIGS. 19 and 20 are plan views illustrating the structure ofa portion of a disc cartridge 306 according to this embodiment fromwhich the cartridge upper shell has been removed. Specifically, FIG. 19illustrates a state where the shutter covers the head opening, whileFIG. 20 illustrates a state where the shutter exposes the head opening.In FIGS. 19 and 20, each member equivalent to the counterpart of thedisc cartridge of the first or fifth embodiment is identified by thesame reference numeral.

The disc cartridge of this embodiment is characterized in that the discholding/interlocking member of the fifth embodiment described above alsofunctions as a shutter. The shutter 46 is provided over the first innersurface 11 u of the cartridge lower shell 11 so as to rotate and slidearound the chucking opening 11 c of the cartridge lower shell 11 asindicated by the arrow 46B in FIGS. 19 and 20. The shutter 46 has a fanshape, or in the shape of a partially notched ring that has an insidediameter equal to the diameter of the chucking opening 11 c.

The shutter 46 includes an engaging pin 46 p that extends toward thecartridge lower shell 11 (i.e., in the direction going into the paper ofFIGS. 19 and 20). The cartridge lower shell 11 is provided with a guidegroove 11 m that engages with this engaging pin 46 p. When the engagingpin 46 p is located at one end of the guide groove 11 m, the headopening 11 h is closed up by the shutter 46. And when the engaging pin46 p is located at the other end of the guide groove 11 m, the headopening 11 h is exposed. The guide groove 11 m is provided along aportion of an arc that is concentric with the chuck opening 11 c. Theguide groove 11 m preferably extends approximately in the direction 1Ain which the disc cartridge is inserted so that the shutter 46 is openedas the disc cartridge is inserted into the disc drive.

Multiple protrusions 46 c, which extend outward and toward the cartridgeupper shell 12 (i.e., in the direction coming out of the paper of FIGS.19 and 20), are provided on the outer periphery of the shutter 46.Furthermore, the upper surface of the shutter 46 is covered with anonwoven fabric or a coating material to prevent the disc 100 fromgetting scratched or any dust from being deposited on the signalrecording side thereof.

A number of disc holding members 43, having a structure similar to thatof the disc holding members of the fifth embodiment, are disposed atpredetermined intervals on respective regions of the cartridge lowershell 11. The disc holding members 43 and the protrusions 46 c of theshutter 46 together hold or release the disc synchronously with themovement of the shutter 46 as already described for the fifthembodiment.

When the disc cartridge of this embodiment is inserted into the discdrive 200 as indicated by the arrow 1A in FIG. 19, the engaging pin 46 pof the shutter 46 will soon contact with a contact member 201 providedfor the disc drive 200. And when the disc cartridge is inserted deeperinto the disc drive 200, the engaging pin 46 p is pressed by the contactmember 201 to start to move along the guide groove 11 m. Then, theshutter 46 starts to rotate around the chucking opening 11 c of thecartridge lower shell 11 as indicated by the arrow 46B. As the shutter46 rotates, the head opening 11 h is opened little by little.

As shown in FIG. 20, when the disc cartridge has been fully insertedinto the disc drive 200, the engaging pin 46 p will reach the other endof the guide groove 11 m. As a result, the head opening 11 h iscompletely exposed. At this point in time, as already described for thefifth embodiment, the protrusions 46 c are located under the discholding members 43. Then, the disc holding portions are pushed up by theprotrusions 46 c toward the cartridge upper shell 12 (i.e., in thedirection coming out of the paper of FIG. 20). As a result, the disc 100that has been held by the disc holding members 43 is released and nowfreely rotatable.

The disc cartridge of this embodiment needs no disc holding/interlockingmember. Thus, compared to the disc cartridge of the fifth embodiment,the disc cartridge can be thinner. Also, if the engaging pin 46 p ismoved manually along the guide groove 11 m, the shutter 46 can be openedand the disc can be released from the disc holding members and removed.

In this embodiment, the shutter 46 rotates clockwise as viewed from overthe cartridge upper shell. However, the shutter 46 may also be rotatedcounterclockwise if the position of the guide groove 11 m is changed.

Embodiment 7

Hereinafter, a seventh embodiment of the present invention will bedescribed. FIGS. 21 and 22 are plan views illustrating the structure ofa portion of a disc cartridge 307 according to this embodiment fromwhich the cartridge upper shell has been removed. Specifically, FIG. 21illustrates a state where the shutter covers the head opening, whileFIG. 22 illustrates a state where the shutter exposes the head opening.In FIGS. 21 and 22, each member equivalent to the counterpart of thedisc cartridge of the third or sixth embodiment is identified by thesame reference numeral.

The disc cartridge of this embodiment is different from the disccartridge of the sixth embodiment in the structure of the disc holdingmembers. Specifically, as shown in FIGS. 21 and 22, the disc cartridgeof this embodiment includes a plurality of disc holding members 17. Justlike the disc holding members of the third embodiment described above,each of these disc holding members 17 also includes an elastic portion17 d. While the shutter 46 is closed, the elastic force applied from theelastic portions 17 d holds the disc in such a manner as to press thedisc 100 toward the center of the disc (17R). In this embodiment, thedisc holding members 17 form integral parts of the cartridge lower shell11. Alternatively, the disc holding members 17 may also be formedseparately from the cartridge lower shell 11.

When a cross section thereof is taken in the disc radial direction, eachof these disc holding members 17 also has a slope that tilts to overhanga portion of the projection area of the disc (i.e., the outer peripheryof the disc) just like the disc holding member 43 shown in FIG. 18.Accordingly, if the disc gets held by the disc holding members 17 so asto have its outer edge contact with the respective slopes, then the discis pressed against the shutter 46.

The shutter 46 includes a plurality of protrusions 46 c on the outerperiphery thereof. In this embodiment, the protrusions 46 c protrudeoutward. Also, the protrusions 46 c are located at such positions on theouter periphery of the shutter 46 as to contact with the elasticportions 17 d of the disc holding members 17 when the shutter 46 isopened.

As shown in FIG. 22, when the shutter 46 is opened, the protrusions 46 cdominate the elastic force of the elastic portions 17 d, thereby pushingthe elastic portions 17 d outward from the disc 100 (i.e., in thedirections 17 s). As a result, the disc 100 is released. However, eachof the disc holding members 17 also includes a rim 17 e at the endthereof. Even after the disc 100 has been released, the rim 17 e stilloverhangs a portion of the projection area of the disc. Accordingly,even if the disc cartridge has been loaded into the disk drive 200 thatis supposed to mount the disc 100 thereon vertically, the disc 100 willnot drop down from the disc cartridge.

The disc cartridge of this embodiment has all the features of the sixthembodiment described above. In addition, the disc holding members 17 mayform integral parts of the cartridge lower shell 11. Thus, the disccartridge can have a simplified structure and its manufacturing cost canbe reduced.

Embodiment 8

Hereinafter, a disc cartridge 308 according to an eighth embodiment ofthe present invention will be described with reference to the drawings.

First, the structure of the disc cartridge 308 will be outlined withreference to FIGS. 23 and 24. As in the first embodiment, the disc 100shown in FIGS. 23 and 24 also includes first and second sides. The firstside of the disc, on which its label, for example, is normally printed,is illustrated in FIG. 23, while the second side of the disc 100, i.e.,the signal recording side 100A, is illustrated as the back surface inFIG. 24.

As shown in FIGS. 23 and 24, the disc cartridge 308 includes a cartridgelower shell 11, a cartridge upper shell 12, a pair of shutters 21 and 22and stopper members 23.

As shown in FIG. 24, the cartridge lower shell 11 includes a chuckingopening 11 c and a head opening 11 h. The chucking opening 11 c isprovided to allow a chucking member (e.g., a spindle motor for rotatingthe disc 100) to enter the disc cartridge 308 externally. The headopening 11 h is provided to allow a head, which reads and/or writes asignal from/on the signal recording side 100A of the disc 100, to enterthe disc cartridge 308 and access the signal recording side 100A. Thecartridge lower shell 11 faces the signal recording side 100A of thedisc 100. Also, the head opening 11 h reaches a side surface of thecartridge lower shell 11.

The cartridge upper shell 12 includes a circular disc window 12 w,through which the disc 100 can be introduced and removed into/from thedisc cartridge 308 and which expands over the entire projection area ofthe disc 100 to expose the upper surface of the disc. The cartridgeupper and lower shells 12 and 11 are adhered or welded together at theirouter periphery, thereby forming a cartridge body 10.

A disc storage portion 10 d for storing the disc 100 therein is definedby a first inner surface 11 u of the cartridge lower shell 11 and asecond inner surface 12 i of the cartridge upper shell 12. The firstinner surface 11 u is opposed to the signal recording side 100A of thedisc 100, while the second inner surface 12 i has a substantiallycylindrical shape and defines the disc window 12 w inside. That is tosay, the first inner surface 11 u becomes the bottom of the disc storageportion 10 d.

In the disc storage portion 10 d, a gap, which is wide enough to allowthe disc 100 to rotate freely, is provided between the second innersurface 12 i and the disc 100. Also, the top of the disc storage portion10 d is the disc window 12 w so that the disc 100 stored in the discstorage portion 10 d has one side thereof exposed inside the disc window12 w.

The stopper members 23 are provided in a removable state for thecartridge upper shell 12 so as to partially protrude into the discwindow 12 w. In this embodiment, two stopper members 23 are provided asshown in FIGS. 23 and 24. On the other hand, a stopper portion 12 s isprovided for the cartridge upper shell 12 so as to protrude into thedisc window 12 w. The stopper portion 12 s forms an integral part of thecartridge upper shell 12. The two stopper members 23 and the stopperportion 12 s are arranged approximately at regular intervals around thecircumference of the disc window 12 w for the purpose of preventing thedisc 100 from dropping down from the disc window 12 w. These stoppermembers 23 and stopper portion 12 s can prevent the droppingparticularly effectively when this disc cartridge is vertically loadedinto a disc drive and used.

The shutters 21 and 22 are disposed between the signal recording side100A of the disc 100 and the inner surface 11 u of the disc storageportion 10 d. The shutters 21 and 22 include rotation holes 21 u and 22u, respectively. These rotation holes 21 u and 22 u are engaged in afreely rotatable state with a pair of rotation shafts 11 s, which islocated outside of the disc storage portion 10 d of the cartridge body10 and opposite to the head opening 11 h. Thus, the shutters 21 and 22rotate on the rotation shafts 11 s in such a manner as to expose orcover the chucking and head openings 11 c and 11 h.

A cam 21 c and a follower 22 c are provided near the rotation holes 21 uand 22 u of the shutters 21 and 22, respectively. The cam 21 c and thefollower 22 c have mutually engaging shapes and together make up aninterlocking mechanism 20 c for opening and closing the shutters 21 and22 while interlocking them with each other.

The respective surfaces of the shutters 21 and 22, which are opposed tothe signal recording side 100A of the disc, are covered with protectivelayers 21 p and 22 p for the purpose of preventing the disc 100 fromgetting scratched or any dust from entering the signal recording side100A thereof.

The protective layers 21 p and 22 p may be appropriately selected fromthe group consisting of an anti-scratching nonwoven fabric, a dustproofnonwoven fabric, an anti-scratching coating layer and a dustproofcoating layer. In this embodiment, sheets of a dustproof nonwoven fabricare adhered or ultrasonic welded as the protective layers 21 p and 22 p.

Shutter springs 31 and 32 are provided outside of the disc storageportion 10 d for the shutters 21 and 22, respectively. These springs 31and 32 apply an elastic force to the shutters 21 and 22 in such adirection as to close the shutters 21 and 22. Optionally, the elasticforce may also be applied from any other type of elastic members to theshutters 21 and 22 in that closing direction.

As shown in FIG. 24, the disc cartridge 308 includes disc holdingportions 21 a, 21 b, 22 a and 22 b at both ends of the shutters 21 and22. Each of these disc holding portions 21 a, 21 b, 22 a and 22 b has adownwardly tapered slope at the end of the shutter 21 or 22 to grip theouter edge of the disc 100 while the shutters 21 and 22 are closed. Thestructure and operation of the disc holding portions 21 a, 21 b, 22 aand 22 b will be described in further detail later.

As shown in FIG. 23, the upper surface of the cartridge body 10 (or thecartridge upper shell 12) has a label plane 10 f, on which the contentsthat have been written on the disc 100 being stored can be noted down,and embossed arrow marks (or concave portions) 10 a that indicate thedirection (the arrow 1A) in which this disc cartridge 308 should beinserted into a disc drive. In addition, two concave portions 10 c arefurther provided on two of the side surfaces of the cartridge body 10that are parallel to the direction 1A in which the cartridge body 10 isinserted. These concave portions 10 c may be used as either pull-innotches or positioning recesses when the disc cartridge 308 is loadedinto a disk drive or when the disc cartridge 308 is stored in a changer.

FIG. 25 is a perspective view illustrating a state where the shutters 21and 22 cover the chucking and head openings 11 c and 11 h with thecartridge upper shell 12 and the disc 100 removed. In FIG. 25, the discholding portions 21 a, 21 b, 22 a and 22 b of the shutters 21 and 22 arelocated at such positions as to grip the outer edge of the disc 100 (notshown).

FIG. 26 is a perspective view illustrating a state where the shutters 21and 22 expose the chucking and head openings 11 c and 11 h with thecartridge upper shell 12 and the disc 100 removed. As a result of therotation of the shutters 21 and 22 on their rotation holes 21 u and 22u, respectively, the chucking and head openings 11 c and 11 h are nowexposed. Also, as the shutters 21 and 22 have rotated, the disc holdingportions 21 a, 21 b, 22 a and 22 b have also rotated on the rotationholes 21 u and 22 u. Consequently, the disc holding portions 21 a, 21 b,22 a and 22 b are now separated from the outer edge of the disc 100 (notshown).

FIG. 27 is a perspective view illustrating a state where the shutters 21and 22 cover the chucking and head openings 11 c and 11 h with the disc100 removed. As shown in FIG. 27, the disc holding portions 21 a, 21 b,22 a and 22 b protrude into the disc storage portion 10 d to hold thedisc 100 (not shown) thereon. On the other hand, FIG. 28 is aperspective view illustrating a state where the shutters 21 and 22expose the chucking and head openings 11 c and 11 h with the disc 100removed. As shown in FIG. 28, while the shutters 21 and 22 are opened,the disc holding portions 21 a, 21 b, 22 a and 22 b are stored outsideof the disc storage portion 10 d of the cartridge body.

Next, the structure and the operation of the shutters 21 and 22 will bedescribed in further detail with reference to FIGS. 29, 30 and 31. FIG.29 is a cross-sectional view as viewed along a plane that passes thecenter of the disc 100. As shown in FIG. 29, the second inner surface 12i of the disc storage portion 10 d of the cartridge body 10 is providedwith a notch 10 w so as not to interfere with the opening and closingoperations of the shutter 22 or 21. Also, the cartridge body 10 furtherincludes a shutter storage portion 10 s for storing a portion of theshutter 22 or 21 being opened. Furthermore, at least the edge portions21 f and 22 f of the shutters 21 and 22, which are butted against eachother over the head and chucking openings 11 h and 11 c while theshutters are closed, overlap with each other in the thickness directionof the disc 100 as shown in FIG. 29.

On the other hand, as shown in FIG. 30, each of the disc holdingportions 21 a, 21 b, 22 a and 22 b includes a slope 21 a′, 21 b′, 22 a′or 22 b′, which overhangs a portion of the projection area of the discand overlaps with the outer edge of the disc 100. That is to say, theslope 21 a′ has a downwardly tapered shape and leans toward the disc100. While the chucking and head openings 11 c and 11 h are covered withthe shutters 21 and 22, the slope 21 a′ is allowed to contact with theouter edge 100 c of the disc 100, thereby gripping the disc 100 thereonand pressing the disc 100 in the thickness direction loot. In thismanner, the signal recording side 100A is brought into plane contactwith the sheets 21 p and 22 p of the shutters 21 and 22 and the disc 100is held and fixed onto the cartridge body 10. In such a state, thesignal recording side 100A of the disc 100 is in close contact with thesheets 21 p and 22 p. Thus, no dust will be deposited on the signalrecording side 100A.

Also, if the exposed side of the disc 100 is rotated manually or if theshutters 21 and 22 are opened or closed intentionally, then dust, fingermarks or any other dirt that has adhered onto the signal recording side100A of the disc 100 may be wiped away.

Furthermore, as shown in FIG. 31, the shutter 21 includes a shutteropening/closing portion 21 t, an elastic portion 21 v and a lockingprotrusion portion 21 k. These portions 21 t, 21 v and 21 k formintegral parts of the shutter 21. Specifically, the shutteropening/closing portion 21 t is for use to open and close the shuttersexternally. The locking protrusion portion 21 k is connected to theshutter 21 by way of the elastic portion 21 v. While the shutter 21covers the chucking and head openings 11 c and 11 h, the lockingprotrusion portion 21 k, to which an elastic force is being applied fromthe elastic portion 21 v, engages with a locking hole 10 k of thecartridge body 10, thereby preventing the shutter 21 from rotating andfixing and supporting the shutter 21 to the cartridge body 10 as shownin FIG. 31. When the shutter 21 is fixed, the other shutter 22, which isinterlocked with the shutter 21 via the interlocking mechanism 20 c, isalso fixed.

Accordingly, only by getting the locking protrusion portion 21 k pressedexternally by a protrusion, for example, in the direction indicated bythe arrow 20A and disengaged from the locking hole 10 k while pressingthe opening/closing portion 21 t in the direction indicated by the arrow20B at the same time, the shutters 21 and 22 can be rotated to exposethe chucking and head openings 11 c and 11 h and the disc 100 can bereleased from the disc holding portions 21 a, 21 b, 22 a and 22 b. Thus,it is possible to prevent the operator from removing the discaccidentally.

Next, the structure and operation of the stopper members 23 will bedescribed in further detail with reference to FIGS. 24 and 32. FIG. 32is a perspective view illustrating the removable stopper member 23upside down. The convex portions 23 a, 23 b and 23 c of the stoppermember 23 are respectively engaged with concave portions 12 a, 12 b and12 c provided for the cartridge upper shell 12 near the disc window 12 wthereof as shown in FIG. 24. Thus, the stopper member 23 can be removedfrom the cartridge upper shell 12.

Next, a mechanism for preventing the erroneous insertion of the disccartridge 308 into a disc drive will be described in further detail withreference to FIG. 33. FIG. 33 is a front view of the disc cartridge 308shown in FIG. 23 as viewed in the direction in which the disc cartridge308 is inserted into a disk drive (i.e., arrow 1B). As shown in FIG. 33,the cartridge body 10 includes a concave portion 10 g on one sidesurface thereof and is asymmetric in the direction 1A in which the disccartridge 308 is inserted into the disc drive (see FIG. 23). The concaveportion log is not located at the center of thickness.

According to such a structure, only when a convex portion, provided forthe disc drive, is fitted with this concave portion 10 g, the disccartridge 308 can be inserted into the disc drive correctly and the discdrive can operate normally.

Stated otherwise, even if one tries to insert the disc cartridge 308into the disc drive upside down by mistake, he or she cannot insert thecartridge 308 into the disc drive. This is because the convex portion ofthe disc drive interferes with the opposite side surface with no concaveportion 10 g. Also, even if one tries to insert the disc cartridge 308into the disc drive upside down and in the wrong way by mistake, he orshe cannot insert the cartridge 308 into the disc drive, either. This isbecause the convex portion of the disc drive also interferes with thenon-recessed portion of the side surface with the concave portion 10 g.Thus, the erroneous insertion can be prevented.

The disc cartridge 308 of this embodiment may be modified in variousmanners.

For example, the thickness of the cartridge body 10 may be furtherreduced to such an extent that the stopper members 23 will not protrudefrom the upper surface 12 f of the cartridge upper shell 12 (see FIG.24) while the shutters 21 and 22 are closed. On the other hand, whilethe shutters 21 and 22 are opened, the stopper members 23 may beprotruded from the upper surface 12 f of the cartridge upper shell 12 inthe following manner. Specifically, as the shutters 21 and 22 are goingto be opened, the disk holding portions 21 a and 22 a, for example, maypush the convex portions 23 a of the stopper members 23 upward whilepassing under the stopper members 23. Then, the stopper members 23 areprotruded from the upper surface 12 f of the cartridge upper shell 12.According to such a structure, a sufficiently broad space can be allowedthe disc 100 to rotate inside the disc storage portion 10 d and yet thedisc cartridge can have its thickness further reduced.

Also, the stopper members 23 may form integral parts of the cartridgebody 10. In that case, the stopper members 23 may be able to be foldedand unfolded.

Furthermore, the shutter springs 31 and 32 may apply an elastic force insuch a direction as to open the shutters 21 and 22. If the shutters canoperate almost completely synchronously by way of the interlockingmechanism, just one of the shutter springs 31 and 32 may be provided.

The locking protrusion portion 21 k forms an integral part of theshutter 21. Alternatively, a locking lever, including a lockingprotrusion portion and a convex portion at the end thereof, may beconnected to the cartridge body 10 via an elastic portion, and anassociated concave portion may be provided for the shutter so that theconvex and concave portions engage with each other. In that case, bypressing the locking protrusion portion through a locking hole of thecartridge body, these convex and concave portions may be disengaged fromeach other so as to allow the shutters to rotate freely. Optionally, thelocking lever, as well as the shutter springs (i.e., elastic members),may be resin springs that form integral parts of the cartridge body 10.

Embodiment 9

Hereinafter, a disc cartridge 309 according to a ninth embodiment of thepresent invention will be described with reference to the drawings.

As shown in FIGS. 34 and 35, the disc cartridge 309 includes a cartridgelower shell 41, a cartridge upper shell 42, stopper members 42 a, 42 b,42 c and 42 d, and a pair of shutters 51 and 52.

As shown in FIG. 35, the cartridge lower shell 41 includes a chuckingopening 41 c and a head opening 41 h. The chucking opening 41 c isprovided to allow a chucking member (e.g., a spindle motor for rotatingthe disc 100) to enter the disc cartridge 309 externally. The headopening 41 h is provided to allow a head, which reads and/or writes asignal from/on the signal recording side 100A of the disc 100, to enterthe disc cartridge 309 and access the signal recording side 100A. Thecartridge lower shell 41 faces the signal recording side 100A of thedisc 100. Also, the head opening 41 h reaches one side surface of thecartridge lower shell 41.

The cartridge upper shell 42 includes a circular disc window 42 w,through which the disc 100 can be introduced and removed into/from thedisc cartridge 309 and which expands over the entire projection area ofthe disc 100 to expose the upper surface of the disc. The cartridgeupper and lower shells 42 and 41 are adhered or welded together at theirouter periphery, thereby forming a cartridge body 40.

A disc storage portion 40 d for storing the disc 100 therein is definedby a first inner surface 41 u of the cartridge lower shell 41 and asecond inner surface 42 i of the cartridge upper shell 42. The firstinner surface 41 u is opposed to the signal recording side 100A of thedisc 100, while the second inner surface 42 i has a substantiallycylindrical shape and defines the disc window 42 w inside. That is tosay, the first inner surface 41 u becomes the bottom of the disc storageportion 40 d.

In the disc storage portion 40 d, a gap, which is wide enough to allowthe disc 100 to rotate freely, is provided between the second innersurface 42 i and the disc 100. Also, the top of the disc storage portion40 d is the disc window 42 w so that the disc 100 stored in the discstorage portion 40 d has one side thereof exposed inside the disc window42 w.

The stopper members 42 a, 42 b, 42 c and 42 d form integral parts of thecartridge upper shell 42 so as to partially protrude into the discwindow 42 w. Each of these stopper members 42 a, 42 b, 42 c and 42 d isseparated from the cartridge upper shell 42 via a slit. These stoppermembers 42 a, 42 b, 42 c and 42 d are used to prevent the disc 100 fromdropping down from the disc window 42 w. The stopper members 42 a, 42 b,42 c and 42 d can prevent the dropping particularly effectively when thedisc cartridge is vertically loaded into a disc drive and used.Optionally, these stopper members 42 a, 42 b, 42 c and 42 d may beintegrated with the cartridge upper shell 42 by way of elastic members.

The shutters 51 and 52 are disposed between the signal recording side100A of the disc 100 and the inner surface 41 u of the disc storageportion 40 d. The shutters 51 and 52 include rotation holes 51 u and 52u, respectively. These rotation holes 51 u and 52 u are engaged in afreely rotatable state with a pair of rotation shafts 41 s, which islocated outside of the disc storage portion 40 d of the cartridge body40 and opposite to the head opening 41 h. Thus, the shutters 51 and 52rotate on the rotation shafts 41 s in such a manner as to expose orcover the chucking and head openings 41 c and 41 h.

A cam 51 c and a follower 52 c are provided near the rotation holes 51 uand 52 u of the shutters 51 and 52, respectively. The cam 51 c and thefollower 52 c have mutually engaging shapes and together make up aninterlocking mechanism 50 c for opening and closing the shutters 51 and52 while interlocking them with each other.

The respective surfaces of the shutters 51 and 52, which are opposed tothe signal recording side 100A of the disc, are covered with protectivelayers 51 p and 52 p for the purpose of preventing the disc 100 fromgetting scratched or any dust from reaching the signal recording side100A thereof.

The protective layers 51 p and 52 p may be appropriately selected fromthe group consisting of an anti-scratching nonwoven fabric, a dustproofnonwoven fabric, an anti-scratching coating layer and a dustproofcoating layer. In this embodiment, sheets of a dustproof nonwoven fabricare adhered or ultrasonic welded as the protective layers 51 p and 52 p.

Shutter springs 61 and 62 are provided outside of the disc storageportion 40 d for the shutters 51 and 52, respectively. These springs 61and 62 apply an elastic force to the shutters 51 and 52 in such adirection as to close the shutters 51 and 52. Alternatively, the shuttersprings 61 and 62 may apply an elastic force to the shutters 51 and 52in such a direction as to open the shutters 51 and 52. Also, if theshutters can operate almost completely synchronously by way of theinterlocking mechanism, only one of the shutter springs 61 and 62 may beprovided.

As in the eighth embodiment, the shutters 51 and 52 include disc holdingportions 51 a, 51 b, 52 a and 52 b at the ends thereof as shown in FIG.35. Furthermore, as will be described in detail later, convex portions51 e and 52 e are provided on respective regions of the shutters 51 and52 so as to be located under the center hole of the disc 100.

As shown in FIG. 34, the upper surface of the cartridge body 40 (or thecartridge upper shell 42) has embossed arrow marks (or concave portions)40 a that indicate the direction (the arrow 1A) in which the disccartridge 309 is inserted into a disc drive. The cartridge body 40further includes two concave portions 40 c on a pair of its sidesurfaces that are parallel to the inserting direction 1A. These concaveportions 40 c may be used as either pull-in notches or positioningrecesses when the disc cartridge 309 is loaded into a disk drive or whenthe cartridge 309 is stored in a changer. Optionally, just one sidesurface of the cartridge 309 may include the concave portion 40 c. Inthat case, the concave portion 40 c may be used as a mechanism forpreventing erroneous (e.g., upside down) insertion when the disccartridge 309 is inserted or loaded into a disk drive. The upper surfaceof the cartridge body 40 further includes a grip portion 40 e thatallows the operator to grip this disc cartridge 309. This grip portion40 e has an antislip embossed shape.

FIG. 36 is a perspective view illustrating a state where the shutters 51and 52 cover the chucking opening 41 c and the head opening 41 h withthe disc 100 removed. FIG. 37 is a perspective view illustrating a statewhere the shutters 51 and 52 expose the chucking opening 41 c and thehead opening 41 h with the disc 100 removed.

Hereinafter, the structure and the operation of the shutters 51 and 52will be described in further detail. As shown in FIGS. 34 and 35, thedisc holding portions 51 a, 51 b, 52 a and 52 b provided for theshutters 51 and 52 also have such a shape as including a slope thattilts in such a manner as to overhang the projection area of the discand to overlap with the outer periphery of the disc 100 as in the eighthembodiment. That is to say, the slope is downwardly tapered and leanstoward the disc 100. Thus, the same effects as those of the eighthembodiment are also achieved.

Also, the shutter 52 includes an opening/closing portion 52 t for use toopen and close the shutters externally, while the shutter 51 includes anelastic portion 51 v and a locking protrusion portion 51 k as integralparts thereof. The locking protrusion portion 51 k is connected to theshutter 51 by way of the elastic portion 51 v. Thus, while the chuckingand head openings 41 c and 41 h are covered with the shutters 51 and 52,the locking protrusion portion 51 k, to which an elastic force isapplied from the elastic portion 51 v, engages with a locking hole 40 kof the cartridge body 40, thereby fixing and supporting the shutter 51in a non-rotatable state to the cartridge body 40. When the shutter 51is fixed, the other shutter 52, which is interlocked with the shutter 51via the interlocking mechanism 50 c, is also fixed.

Accordingly, only by getting the locking protrusion portion 51 k pressedexternally by a protrusion, for example, in the direction indicated bythe arrow 50A and disengaged from the locking hole 40 k while pressingthe opening/closing portion 52 t in the direction indicated by the arrow50B at the same time as shown in FIG. 36, the shutters 51 and 52 can berotated to expose the chucking and head openings 41 c and 41 h and thedisc 100 can be released from the disc holding portions 51 a, 51 b, 52 aand 52 b. Thus, it is possible to prevent the operator from removing thedisc 100 accidentally.

Also, unlike the eighth embodiment, the locking protrusion portion 51 kand the opening/closing portion 52 t are provided for the two differentshutters 51 and 52. Such a structure is particularly effective for adisc cartridge for a disc of a small diameter. This is because a disccartridge for a disc of a small diameter and the shutters thereof shouldhave relatively small sizes and it is normally difficult to provide thelocking protrusion portion and opening/closing portion for a singleshutter out of design considerations. Also, even when a single shuttercan include both the locking protrusion portion and the opening/closingportion, a very narrow gap would be allowed between a shutteropening/closing mechanism and an unlocking mechanism on the disc driveside or these two mechanisms need to be provided within a very limitedspace, thus making it hard to design the disc drive as intended.

The locking protrusion portion 51 k forms an integral part of theshutter 51. Alternatively, a locking lever, including a lockingprotrusion portion and a convex portion at the end thereof, may beconnected to the cartridge body 40 by way of an elastic portion, and anassociated concave portion may be provided for the shutter so that theconvex and concave portions engage with each other. In that case, bypressing the locking protrusion portion through a locking hole of thecartridge body, these convex and concave portions may be disengaged fromeach other so as to allow the shutters to rotate freely. Optionally, inthat case, the locking lever, as well as the shutter springs (i.e.,elastic members), may be resin springs that form integral parts of thecartridge body 40.

Next, it will be described how the convex portions 51 e and 52 e on theshutters 51 and 52 work. FIG. 38 is a cross-sectional view illustratingthe center of the disc and its surrounding portions as viewed along aplane that passes the center of the disc 100. As shown in FIG. 38, whilethe shutters 51 and 52 are closed, the convex portions 51 e and 52 eprotrude into the center hole 100 h and the disc 100 is now in planecontact with the shutters 51 and 52.

As shown in FIG. 39, while the shutters 51 and 52 are going to beopened, the convex portions 51 e and 52 e slide from inside the centerhole 100 h into under the lower surface of the disc 100, thereby liftingthe disc 100 and bringing the disc 100 out of plane contact with theshutters 51 and 52. In this manner, while the shutters 51 and 52 aregoing to be opened or closed, the signal recording side 100A will notget scratched by the shutters 51 and 52. Also, it is inside the signalrecording area of the signal recording side 100A that the convexportions 51 e and 52 e move along with the shutters 51 and 52 beingopened or closed. Accordingly, the convex portions 51 e and 52 e nevercontact with, or scratch, the signal recording area.

Next, the structure and operation of the stopper members will bedescribed with reference to FIGS. 40 and 41. FIG. 40 is across-sectional view illustrating a portion surrounding the disc outerperiphery as viewed along a plane that passes the center of the disc100. A convex portion 42 c′, (42 a′, 42 b′ or 42 d′) has been formed onthe bottom of the stopper member 42 c, (42 a, 42 b or 42 d). While theshutters 51 and 52 are closed, the stopper member 42 c is substantiallyparallel to the disc 100 and falls within the thickness of the cartridge309 as shown in FIG. 40. An appearance of the disc cartridge 309 in sucha state is illustrated in FIG. 36.

On the other hand, while the shutters 51 and 52 are opened, the slopeportions 52 f, 51 f, 51 d and 52 d of the shutters 51 and 52 contactwith the convex portions 42 a′, 42 b′, 42 c′ and or 42 d′, respectively,thereby lifting the stopper members 42 a, 42 b, 42 c and 42 d to abovethe disc 100 as shown in FIG. 41. An appearance of the disc cartridge309 in such a state is illustrated in FIG. 37. By using such astructure, particularly in an interval after the disc cartridge 309 hasbeen vertically loaded into a disc drive and before the disc 100 getschucked, it is possible to prevent the disc 100 from dropping down fromthe cartridge 309. In addition, while the disc 100 is being chucked, thedisc 100 can move in a broader space. Furthermore, this structure alsocontributes to further reducing the thickness of the cartridge body.

It should be noted that to keep the shutters 51 and 52 temporarilyopened for a while, the slope portion 52 f, (51 f, 51 d or 52 d) mayhave a convex or concave portion that engages with the convex portion 42a′, (42 b′, 42 c′ or 42 d′).

Embodiment 10

Hereinafter, a disc cartridge 310 according to a tenth embodiment of thepresent invention will be described with reference to the drawings. Thedisc cartridge 310 of this embodiment is mainly characterized in thatstopper members are provided for the shutters.

As shown in FIGS. 42 and 43, the disc cartridge 310 includes a cartridgelower shell 71, a cartridge upper shell 72, stopper members 81 d, 81 fand 82 d, and a pair of shutters 81 and 82.

As shown in FIG. 43, the cartridge lower shell 71 includes a chuckingopening 71 c and a head opening 71 h. The chucking opening 71 c isprovided to allow a chucking member (e.g., a spindle motor for rotatingthe disc 100) to enter the disc cartridge 310 externally. The headopening 71 h is provided to allow a head, which reads and/or writes asignal from/on the signal recording side 100A of the disc 100, to enterthe disc cartridge 310 and access the signal recording side 100A. Thecartridge lower shell 71 faces the signal recording side 100A of thedisc 100. Also, the head opening 71 h reaches one side surface of thecartridge lower shell 71.

The cartridge upper shell 72 includes a circular disc window 72 w,through which the disc 100 can be introduced and removed into/from thedisc cartridge 310 and which expands over the entire projection area ofthe disc 100 to expose the upper surface of the disc 100. The cartridgeupper and lower shells 72 and 71 are adhered or welded together at theirouter periphery, thereby forming a cartridge body 70.

A disc storage portion 70 d for storing the disc 100 therein is definedby a first inner surface 71 u of the cartridge lower shell 71 and asecond inner surface 72 i of the cartridge upper shell 72. The firstinner surface 71 u is opposed to the signal recording side 100A of thedisc 100, while the second inner surface 72 i has a substantiallycylindrical shape and defines the disc window 72 w inside. That is tosay, the first inner surface 71 u becomes the bottom of the disc storageportion 70 d.

In the disc storage portion 70 d, a gap, which is wide enough to allowthe disc 100 to rotate freely, is provided between the second innersurface 72 i and the disc 100. Also, the top of the disc storage portion70 d is the disc window 72 w so that the disc 100 stored in the discstorage portion 70 d has one side thereof exposed inside the disc window72 w.

The shutters 81 and 82 are disposed between the signal recording side100A of the disc 100 and the inner surface 71 u of the disc storageportion 70 d. The shutters 81 and 82 include rotation holes 81 u and 82u, respectively. These rotation holes 81 u and 82 u are engaged in afreely rotatable state with a pair of rotation shafts 71 s, which islocated outside of the disc storage portion 70 d of the cartridge body70 and opposite to the head opening 71 h. Thus, the shutters 81 and 82rotate on the rotation shafts 71 s in such a manner as to expose orcover the chucking and head openings 71 c and 71 h.

A cam 81 c and a follower 82 c are provided near the rotation holes 81 uand 82 u of the shutters 81 and 82, respectively. The cam 81 c and thefollower 82 c have mutually engaging shapes and together make up aninterlocking mechanism 80 c for opening and closing the shutters 81 and82 while interlocking them with each other.

The respective surfaces of the shutters 81 and 82, which are opposed tothe signal recording side 100A of the disc, are covered with protectivelayers 81 p and 82 p for the purpose of preventing the disc 100 fromgetting scratched or any dust from entering the signal recording side100A thereof.

The protective layers 81 p and 82 p may be appropriately selected fromthe group consisting of an anti-scratching nonwoven fabric, a dustproofnonwoven fabric, an anti-scratching coating layer and a dustproofcoating layer. In this embodiment, sheets of a dustproof nonwoven fabricare adhered or ultrasonic welded as the protective layers 81 p and 82 p.

Shutter springs 91 and 92 are provided outside of the disc storageportion 70 d for the shutters 81 and 82, respectively. These springs 91and 92 apply an elastic force to the shutters 81 and 82 in such adirection as to close the shutters 81 and 82. Alternatively, the shuttersprings 91 and 92 may apply an elastic force to the shutters 81 and 82in such a direction as to open the shutters 81 and 82. Also, if theshutters can operate almost completely synchronously by way of theinterlocking mechanism, only one of the shutter springs 91 and 92 may beprovided.

As in the eighth embodiment, the shutters 81 and 82 include disc holdingportions 81 a, 81 b, 82 a and 82 b at the ends thereof as shown in FIG.43. Convex portions 81 e and 82 e are also formed on the shutters 81 and82, respectively.

Furthermore, as will be described in detail later, the stopper members81 f, 81 d and 82 d are provided as integral parts of the shutters 81and 82 near the disc holding portions 81 a, 81 b and 82 b of theshutters 81 and 82, respectively. Alternatively, these stopper members81 f, 81 d and 82 d may be integrated with the shutters 81 and 82 by wayof elastic members.

As shown in FIG. 42, the upper surface of the cartridge body 70 (or thecartridge upper shell 72) has embossed arrow marks (or concave portions)70 a that indicate the direction (the arrow 1A) in which this disccartridge 310 should be inserted into a disc drive. The cartridge body70 further includes two concave portions 70 c on a pair of its sidesurfaces that are parallel to the inserting direction 1A. These concaveportions 70 c may be used as either pull-in notches or positioningrecesses when the disc cartridge 310 is loaded into a disk drive or whenthe cartridge 310 is stored in a changer. Optionally, just one sidesurface of the cartridge 310 may include the concave portion 70 c. Inthat case, the concave portion 70 c may be used as a mechanism forpreventing erroneous (e.g., upside down) insertion when the disccartridge 310 is inserted or loaded into a disk drive. The upper surfaceof the cartridge body 70 further includes a grip portion 70 e thatallows the operator to grip the cartridge 310. This grip portion 70 ehas an antislip embossed shape.

FIG. 44 is a perspective view illustrating a state where the shutters 81and 82 cover the chucking opening 71 c and the head opening 71 h withthe disc 100 removed. FIG. 45 is a perspective view illustrating a statewhere the shutters 81 and 82 expose the chucking opening 71 c and thehead opening 71 h with the disc 100 removed.

Hereinafter, the structure and the operation of the shutters 81 and 82will be described in further detail. As shown in FIGS. 42 and 43, thedisc holding portions 81 a, 81 b, 82 a and 82 b provided for theshutters 81 and 82 have such a shape as including a slope that tilts insuch a manner as to overhang the projection area of the disc and tooverlap with the outer periphery of the disc 100 as in the eighthembodiment. That is to say, the slope is downwardly tapered and leanstoward the disc 100. Thus, the same effects as those of the eighthembodiment are also achieved.

Also, the shutter 82 includes an opening/closing portion 82 t for use toopen and close the shutters externally, an elastic portion 82 v and alocking protrusion portion 82 k as integral parts thereof. The lockingprotrusion portion 82 k is connected to the shutter 82 by way of theelastic portion 82 v. Thus, while the chucking and head openings 71 cand 71 h are covered with the shutters 81 and 82, the locking protrusionportion 82 k, to which an elastic force is applied from the elasticportion 82 v, engages with a locking hole 70 k of the cartridge body 70as shown in FIG. 44, thereby fixing and supporting the shutter 82 in anon-rotatable state to the cartridge body 70. When the shutter 82 isfixed, the other shutter 82, which is interlocked with the shutter 82via the interlocking mechanism 80 c, is also fixed.

Accordingly, only by getting the locking protrusion portion 82 k pressedexternally by a protrusion, for example, in the direction indicated bythe arrow 70A and disengaged from the locking hole 70 k while pressingthe opening/closing portion 82 t in the direction indicated by the arrow70B at the same time as shown in FIG. 44, the shutters 81 and 82 can berotated to expose the chucking and head openings 71 c and 71 h and thedisc 100 can be released from the disc holding portions 81 a, 81 b, 82 aand 82 b. Thus, it is possible to prevent the operator from removing thedisc accidentally.

The locking protrusion portion 82 k forms an integral part of theshutter 82. Alternatively, a locking lever, including a lockingprotrusion portion and a convex portion at the end thereof, may beconnected to the cartridge body 70 by way of an elastic portion, and aconcave portion may be provided for the shutter so that the convex andconcave portions engage with each other. In that case, by pressing thelocking protrusion portion through a locking hole of the cartridge body,these convex and concave portions may be disengaged from each other soas to allow the shutters to rotate freely. Optionally, in that case, thelocking lever, as well as the shutter springs (i.e., elastic members),may be resin springs that form integral parts of the cartridge body 70.

Next, the structure and operation of the stopper members 81 f, 81 d and82 d will be described in further detail. While the shutters 81 and 82are closed, the stopper members 81 f, 81 d and 82 d are substantiallyparallel to the disc 100 and do not protrude from the upper surface ofthe disc cartridge 310 as shown in FIGS. 46 and 48. An appearance of thedisc cartridge 310 in such a state is illustrated in FIG. 44.

On the other hand, while the shutters 81 and 82 are going to be opened,the stopper members 81 f, 81 d and 82 d are guided by a slit 70 s and asloped portion 72 s of the cartridge body 70 so as to be lifted to abovethe disc 100 as shown in FIGS. 47 and 49. The slit 70 s is formed in theinner sidewall portion of the cartridge body 70, while the slopedportion 72 s is formed on the inner upper wall of the cartridge body 70.Also, the cartridge upper shell 72 is provided with notched portions 72a, 72 b and 72 c so as not to interfere with the stopper members 81 f,81 d and 82 d that have been lifted up. An appearance of the disccartridge 310 in such a state is illustrated in FIG. 45.

While the shutters 81 and,82 are closed, the stopper members 81 f, 81 dand 82 d overhang the projection area of the disc 100 and are locatedover the disc 100. Thus, the stopper members 81 f, 81 d and 82 d pressthe disc 100 against the shutters 81 and 82 in the thickness direction,thereby holding the disc 100 thereon. Accordingly, the disc holdingportions 81 a, 81 b, 82 a and 82 b may be omitted from the shutters 81and 82.

According to such a structure, particularly in an interval after thedisc cartridge 310 has been vertically loaded into a disc drive andbefore the disc 100 gets chucked, it is possible to prevent the disc 100from dropping down from the disc cartridge 310. In addition, while thedisc 100 is being chucked, the disc 100 can move in a broader space.Furthermore, this structure also contributes to further reducing thethickness of the cartridge body.

Embodiment 11

Hereinafter, a disc cartridge 311 according to an eleventh embodiment ofthe present invention will be described with reference to the drawings.

As shown in FIGS. 50 and 51, the disc cartridge 311 includes a cartridgelower shell 11, a cartridge upper shell 12, a pair of shutters 21 and 22and stopper members 23. As shown in FIGS. 52 through 56, the structuresand functions of all of these members are the same as those alreadydescribed for the eighth embodiment and the detailed description thereofwill be omitted herein.

Unlike the disc cartridge 308 of the eighth embodiment, the shutters 21and 22 of the disc cartridge 311 of this embodiment have a hole 20 h asshown in FIGS. 50 and 51.

More specifically, while the shutters 21 and 22 of the disc cartridge311 are closed, the shutters 21 and 22 define the hole 20 h just underthe center hole 100 h of the disc 100. The hole 20 h is made up of twonotches 21 h and 22 h provided for the shutters 21 and 22, respectively.

If the disc cartridge 311 is left with the upper surface of the disc 100exposed upward as shown in FIG. 50, dust may pass through the centerhole 100 h. Even so, in this structure, the dust should pass and go outthrough the hole 20 h of the shutters 21 and 22 without remaining insidethe disc cartridge 311, or without being deposited on the shutters 21and 22. Thus, when the shutters 21 and 22 are opened (i.e., when thisdisc cartridge 311 is loaded into a disc drive), no dust will have beendeposited on the signal recording side 100A of the disc.

Considering the disc cartridge 311 may be left either upside up as shownin FIG. 50 or upside down (i.e., with the cartridge lower shell 11facing upward), the hole 20 h preferably has a diameter that isapproximately equal to that of the center hole 100 h. This is because ifsuch a relationship is satisfied, dust will be deposited neither on theshutters 21 and 22 when the disc cartridge 311 is left upside up nor onthe signal recording side 100A of the disc 100 when the disc cartridge311 is left upside down.

In this disc cartridge 311, the opening/closing portion for use to openand close the shutters 21 and 22 is provided for the shutter 22 unlikethe disc cartridge 308 of the eighth embodiment. More specifically, asshown in FIGS. 51 and 57, the opening/closing portion 22 t, elasticportion 22 v and locking protrusion portion 22 k are provided asintegral parts of the shutter 22. The locking protrusion portion 22 k isconnected to the shutter 22 by way of the elastic portion 22 v.Accordingly, unlike the eighth embodiment, the opening/closing portion22 t is located on the right-hand side of the head opening 11 h withrespect to the disc 100. The function and the operation of theopening/closing portion 22 t are the same as those described for thedisc cartridge 308 of the eighth embodiment.

Embodiment 12

Hereinafter, a disc cartridge 312 according to a twelfth embodiment ofthe present invention will be described with reference to the drawings.

Unlike the disc cartridge 311 of the eleventh embodiment, the disccartridge 312 includes a rim 12 t around the inner side surface 12 i ofthe disc storage portion 10 d and a convex portion 20 w around the hole20 h defined by the shutters 21 and 22. These features will be describedbelow.

As shown in FIG. 58, the rim 12 t protrudes from the inner side surface12 i of the cartridge upper shell 12 toward the inner periphery of thedisc 100 and substantially surrounds the outer periphery of the discstorage portion 10 d. FIG. 59 shows a cross section of the disccartridge 312 in a state where the disc 100 is stored in the discstorage portion 10 d. While the shutters 21 and 22 are closed, the outeredge of the signal recording side 100A of the disc 100 contacts with therim 12 t as shown in FIG. 59. As a result, the gap between the outerperiphery of the disc 100 and the cartridge body is closed, therebypreventing any dust from reaching the signal recording side 100A.

Also, a gap 10 w is provided between the rim 12 t of the cartridge body10 and the cartridge lower shell 11. Thus, when the shutters 21 and 22are opened, respective portions of the shutters 21 and 22 enter the gap10 w as shown in FIGS. 60 and 61. In this manner, it is possible toprevent the shutters 21 and 22 from interfering with the cartridge body10.

In such a structure, however, while the shutters 21 and 22 are closed,another gap 10 z that leads to the open air is also created between thedisc 100 and the shutters 21 and 22 as shown in FIG. 59. To close thisgap 10 z, the shutters 21 and 22 include convex portions 21 w and 22 w,respectively, around the center hole 100 h of the disc. As shown in FIG.58, when the shutters 21 and 22 are closed, these convex portions 21 wand 22 w are in tight contact with each other, thereby forming theconvex portion 20 w that closes the gap 10 z around the entire disccenter hole 100 h. As a result, no dust will reach the signal recordingside 100A of the disc 100 through the disc center hole 100 h.

However, the top of these convex portions 21 w and 22 w might contactwith the signal recording side 100A of the disc 100. Accordingly, theedge of the convex portions 21 w and 22 w should preferably be round soas not to scratch the disc. optionally, the convex portions 21 w and 22w may form integral parts of the shutters 21 and 22, respectively. Inthat case, an anti-scratching nonwoven fabric is preferably adhered orultrasonic welded to that portion of the convex portion 20 w thatcontacts with the disc 100 or an anti-scratching coating is preferablyformed on that portion. Alternatively, the convex portions 21 w and 22 wthemselves may be made of an anti-scratching nonwoven fabric or ananti-scratching coating and directly ultrasonic welded or bonded to theshutters 21 and 22, respectively.

Also, as shown in FIG. 59, while the shutters 21 and 22 are closed, thedisc 100 is held by the shutters 21 and 22 so as to be lifted by theconvex portion 20 w and the rim 12 t over the shutters 21 and 22 withthe gap 10 z left between them. That is to say, most of the signalrecording side 100A of the disc 100 is not in plane contact with theshutters 21 and 22. Accordingly, even if the shutters 21 and 22 aresubjected to no treatment (e.g., even when no anti-scratching nonwovenfabric is attached thereto), the signal recording side 100A still willnot get scratched.

FIGS. 62 and 63 illustrate a disc cartridge including alternative convexportions 21 w′ and 22 w′ that have been expanded toward the outerperiphery of the disc 100. Specifically, FIG. 62 illustrates a statewhere the shutters 21 and 22 are closed, while FIG. 63 illustrates astate where the shutters 21 and 22 are opened.

As shown in FIGS. 62 and 63, while the shutters 21 and 22 are opened,the convex portions 21 w′ and 22 w′ are preferably located inside therim 12 t of the disc storage portion 10 d (i.e., closer to the center ofthe disc storage portion). Then, the convex portions 21 w′ and 22 w′will not contact with, or interfere with, the rim 12 t.

Optionally, the convex portions 21 w′ and 22 w′ may form integral partsof the shutters 21 and 22, respectively. In that case, ananti-scratching nonwoven fabric is preferably adhered or ultrasonicwelded to those portions of the convex portions 21 w′ and 22 w′ thatcontact with the disc 100 or an anti-scratching coating is preferablyformed thereon. Alternatively, the convex portions 21 w′ and 22 w′themselves may be made of an anti-scratching nonwoven fabric or ananti-scratching coating and directly ultrasonic welded or bonded to theshutters 21 and 22, respectively.

Embodiment 13

Hereinafter, a disc cartridge 313 according to a thirteenth embodimentof the present invention will be described with reference to thedrawings.

First, the structure of the disc cartridge 313 will be outlined withreference to FIGS. 64 and 65. As in the eighth embodiment, the disc 100shown in FIGS. 64 and 65 also has first and second sides. The firstside, on which the label of the disc, for example, is normally printed,is illustrated in FIG. 64, while the second side of the disc 100, i.e.,the signal recording side 100A, is illustrated as the back surface inFIG. 65.

As shown in FIGS. 64 and 65, the disc cartridge 313 includes a cartridgelower shell 11, a cartridge upper shell 12, a pair of shutters 21 and 22and stopper members 23.

As shown in FIG. 65, the cartridge lower shell 11 includes a chuckingopening 11 c and a head opening 11 h. The chucking opening 11 c isprovided to allow a chucking member (e.g., a spindle motor for rotatingthe disc 100) to enter the disc cartridge 313 externally. The headopening 11 h is provided to allow a head, which reads and/or writes asignal from/on the signal recording side 100A of the disc 100, to enterthe disc cartridge 313 and access the signal recording side 100A. Thecartridge lower shell 11 faces the signal recording side 100A of thedisc 100. The cartridge lower shell 11 is formed by molding a syntheticresin.

The head opening 11 reaches one side surface of the cartridge lowershell 11. To minimize a decrease in rigidity of the cartridge lowershell 11 due to the presence of the head opening 11 h, the cartridgelower shell 11 includes a bridge portion 11 b that links both ends ofthe head opening 11 h together.

The bottom of the cartridge lower shell 11 further includes twopositioning holes 11 w into which cartridge positioning pins of a discdrive are inserted.

The cartridge upper shell 12 includes a circular disc window 12 w,through which the disc 100 can be introduced and removed into/from thedisc cartridge 313 and which expands over the entire projection area ofthe disc 100 to expose the upper surface of the disc 100. The cartridgeupper and lower shells 12 and 11 are adhered or welded together at theirouter periphery, thereby forming a cartridge body 10. The cartridgeupper shell 12 is also made of a synthetic resin.

A disc storage portion 10 d for storing the disc 100 therein is definedby a first inner surface 11 u of the cartridge lower shell 11 and asecond inner surface 12 i of the cartridge upper shell 12. The firstinner surface 11 u is opposed to the signal recording side 100A of thedisc 100, while the second inner surface 12 i has a substantiallycylindrical shape and defines the disc window 12 w inside. That is tosay, the first inner surface 11 u becomes the bottom of the disc storageportion 10 d.

In the disc storage portion 10 d, a gap, which is wide enough to allowthe disc 100 to rotate freely, is provided between the second innersurface 12 i and the disc 100. Also, the top of the disc storage portion10 d is the disc window 12 w so that the disc 100 stored in the discstorage portion 10 d has one side thereof exposed inside the disc window12 w.

The stopper members 23 are provided in a removable state for thecartridge upper shell 12 so as to partially protrude into the discwindow 12 w. As shown in FIGS. 64 and 65, two stopper members 23 areprovided in this embodiment. On the other hand, a stopper portion 12 sis provided for the cartridge upper shell 12 so as to protrude into thedisc window 12 w. The stopper portion 12 s forms an integral part of thecartridge upper shell 12. The two stopper members 23 and the stopperportion 12 s are arranged approximately at regular intervals around thecircumference of the disc window 12 w for the purpose of preventing thedisc 100 from dropping down from the disc window 12 w. Also, two convexdisc contact portions 12 s′ are formed on the stopper portion 12 s. Forthe disc 100, these disc contact portions 12 s′ are as high as the disccontact portions 23 a of the stopper members 23.

According to this structure, even if the disc cartridge 313 is mountedvertically or upside down, the disc 100 still can be kept in a fixedposition. That is to say, when the disc cartridge 313 is insertedvertically or upside down into a disc drive, the dropping can beprevented particularly effectively. It should be noted that the stoppermembers 23 do not have to be removable from the cartridge body 10.Alternatively, as long as the stopper members 23 can be rotated orturned inside the disc storage portion 10 d to such an extent as toallow the operator to remove the disc 100 from the cartridge body 10,the stopper members 23 may also be secured to the cartridge upper shell12.

The shutters 21 and 22 lie on a single plane between the signalrecording side 100A of the disc 100 and the inner surface 11 u of thedisc storage portion 10 d. The shutters 21 and 22 include rotation holes21 u and 22 u, respectively. These rotation holes 21 u and 22 u areengaged in a freely rotatable state with a pair of rotation shafts 11 s,which is located outside of the disc storage portion 10 d of thecartridge body 10 and opposite to the head opening 11 h. Thus, theshutters 21 and 22 rotate on the rotation shafts 11 s in such a manneras to expose or cover the chucking and head openings 11 c and 11 h. Theshutters 21 and 22 are also made of a synthetic resin.

A ring-shaped portion 21 c and a pin-shaped portion 22 c are providednear the rotation holes 21 u and 22 u of the shutters 21 and 22,respectively. The ring-shaped portion 21 c and the pin-shaped portion 22c have mutually engaging shapes and together make up an interlockingmechanism 20 c for opening and closing the shutters 21 and 22 whileinterlocking them with each other. The interlocking mechanism 20 c mayalso be any other interlocking mechanism such as a cam mechanism or agear mechanism.

The respective surfaces of the shutters 21 and 22, which are opposed tothe signal recording side 100A of the disc, are covered with protectivelayers 21 p and 22 p for the purpose of preventing the disc 100 fromgetting scratched or any dust from entering the signal recording side100A thereof.

The protective layers 21 p and 22 p may be appropriately selected fromthe group consisting of an anti-scratching nonwoven fabric, a dustproofnonwoven fabric, an anti-scratching coating layer and a dustproofcoating layer. In this embodiment, sheets of a dustproof nonwoven fabricare adhered or ultrasonic welded as the protective layers 21 p and 22 p.

A locking protrusion portion 21 k is provided for the shutter 21, whilea locking engaging portion 22 k, which engages with the lockingprotrusion portion 21 k, is provided for the shutter 22. The lockingprotrusion portion 21 k and locking engaging portion 22 k together makeup a locking mechanism 20 k for locking and unlocking the shutters 21and 22 to/from each other. By using this structure, the shutters 21 and22 can be locked and unlocked, thus preventing the operator from openingthe shutters accidentally. In addition, the signal recording side 100Aof the disc 100 can be protected from dust, finger marks or scratches.The locking protrusion portion 21 k and the locking engaging portion 22k form integral parts of the shutters 21 and 22, respectively.

Furthermore, the shutters 21 and 22 are provided with notches 21 h and22 h, respectively. When the shutters 21 and 22 are closed, thesenotches 21 h and 22 h contact with each other to form a hole 20 h. Whilethe shutters 21 and 22 are closed, the hole 20 h is located just underthe center hole 10 h of the disc 100. The diameter of the hole 20 h isapproximately equal to that of the center hole 100 h of the disc 100. Insuch a structure, even if this disc cartridge 313 is left with theupside up, no dust will be deposited on the shutters 21 and 22. Also,even if the disc cartridge 313 is left upside down, no dust will bedirectly deposited on the signal recording side 100A of the disc 100,either.

As described for the eighth embodiment, the shutters 21 and 22 includedisc holding portions 21 a, 21 b, 22 a, and 22 b for holding the disc100 thereon while the shutters are closed. The disc holding portions 21a, 21 b, 22 a and 22 b have been molded integrally with the shutters 21and 22 so as to be dispersed around the circumference of the disc. Eachof these disc holding portions 21 a, 21 b, 22 a and 22 b has adownwardly tapered slope to contact with the disc 100. By providingthese slopes, the disc 100 can be held firmly and pressed against theshutters 21 and 22 while the shutters 21 and 22 are closed.

In this embodiment, only the disc holding portion 21 b is not secured tothe shutter 21 but is connected thereto via an elastic portion 21 d andis freely rotatable in the radial direction of the disc 100 (i.e.,toward the center of the disc). Accordingly, the disc holding portions21 a, 21 b, 22 a and 22 b can firmly hold a disc 100 having any ofvarious diameters or thicknesses without allowing the disc 100 to moveinconstantly.

A shutter opening/closing portion 22 t for use to open and close theshutter 22 is formed as an integral part of the shutter 22 so as to beopposed to the rotation hole 22 u, i.e., near the disc holding portion22 a. When the shutters 21 and 22 are attached to the cartridge body 10,the shutter opening/closing portion 22 t is located under the bridgeportion 11 b and inside the head opening 11 h. In opening or closing theshutters 21 and 22, the opening/closing portion 22 t is moved along thebridge portion 11 b inside the head opening 11 h. In this arrangement,there is no need to separately provide any gap for allowing the shutteropening/closing portion 21 t to move therein for the cartridge body 10.In other words, since there is no need to provide an extra gap for thecartridge body 10, no dust will enter the cartridge body 10unnecessarily. Furthermore, the shutter opening/closing portion 22 t canbe disposed inside the head opening 11 h of the cartridge body 10, thusproviding a cartridge of a good design.

As shown in FIG. 66, the shutters 21 and 22 are not entirely in contactwith each other along a line but have a plurality of contact surfacesthat are not aligned with the line. More specifically, the shutters 21and 22 have a first pair of contact surfaces 21 f and 22 f over thechucking opening 11 c and a second pair of contact surfaces 21 g and 22g over the head opening 11 h, respectively. In this embodiment, thecontact surfaces 21 f and 22 f contact with each other along thecenter-of-symmetry line of the disc cartridge 313. On the other hand,the contact surfaces 21 g and 22 g contact with each other along a linethat defines a predetermined angle (e.g., approximately 15 to 16degrees) with the center-of-symmetry line. When the shutters 21 and 22have such shapes, the shutter 22 can have an integral shape from thevicinity of the shutter opening/closing portion 22 t and can havesufficiently high rigidity.

Shutter springs 31 and 32 are provided outside of the disc storageportion 10 d for the shutters 21 and 22, respectively. These springs 31and 32 apply an elastic force to the shutters 21 and 22 in such adirection as to close the shutters 21 and 22. The shutter springs 31 and32 are inserted into two spring poles lit provided for the cartridgelower shell 11. In this embodiment, torsion coil springs are used as theshutter springs 31 and 32. Springs of the same shape are used as theshutter springs 31 and 32 to reduce the cost. Examples of other elasticmembers that may be used as the shutter springs include compressionsprings, leaf springs and elastic resin springs.

As shown in FIG. 65, the disc cartridge 313 includes a write protectmember 40, which is inserted into a groove portion 11 v of the cartridgelower shell 11 so as to slide along the groove portion 11 v. By slidingthe write protect member 40, the convex portion 40 t thereof isdisplaced. Thus, in accordance with the position of the convex portion40 t, a sensor switch provided for a disc drive is turned ON or OFF. Inthis manner, writing on the disc 100 may be either prohibited orallowed.

This disc cartridge 313 is made up of the cartridge body 10 consistingof the cartridge lower and upper shells 11 and 12, stopper members 23,shutters 21 and 22, shutter springs 31 and 32, and write protect member40.

When the cartridge lower and upper shells 11 and 12 are joined together,the two rotation shafts 11 s of the cartridge lower shell 11 are engagedwith two concave portions 12 h of the cartridge upper shell 12. In thismanner, the rotation shafts 11 s can have their rigidity increased.Thus, even when the shutters 21 and 22 are open, reduced torsion iscreated around the respective centers of rotation of the shutters by theelastic force applied from the shutter springs 31 and 32. As a result,the shutters can be opened to the intended angle.

The upper surface of the cartridge body 10 (or the cartridge upper shell12) has a label plane 10 f, on which the contents that have been writtenon the disc 100 stored can be noted down, and an embossed arrow mark (orconcave portion) 10 a that indicates the direction (the arrow 1A) inwhich this disc cartridge 313 is inserted into a disc drive.

The cartridge body 10 further includes two pairs of concave portions 10c and 10 e on two side surfaces thereof that are parallel to theinserting direction 1A. These concave portions 10 c and 10 e may be usedas either pull-in notches or positioning recesses when the disccartridge 313 is loaded into a disk drive or when the disc cartridge 313is stored in a changer. The cartridge body further includes a slitportion 10 b on one of its side surfaces. The slit portion 10 b may beused as a recess to identify the upside and downside of the disccartridge 313 when this disc cartridge 313 is inserted into the discdrive.

Hereinafter, it will be described with reference to FIGS. 66, 67, 68 and69 how this disc cartridge 313 operates. FIGS. 66 and 67 illustrate astate where the shutters are closed and a state where the shutters areopened, respectively. FIG. 68 illustrates the details of the shutterlocking portion. And FIG. 69 illustrates the details of the disc holdingportion of the shutter.

First, a storage state of the disc cartridge 313, i.e., a state of thedisc cartridge 313 that has not been loaded into a disc drive yet, willbe described. In that state, the shutters 21 and 22 are closed as shownin FIG. 66. Also, as shown in FIG. 69, the sloped portion 22 a′ of thedisc holding portion 22 a of the shutter 22 contacts with the outer edgeof the disc 100, thereby holding the disc 100 thereon and pressing thedisc 100 in the thickness direction 100 t. In this manner, the signalrecording side 100A is brought into plane contact with the sheet 22 p ofthe shutter 22 and the disc 100 is held and fixed onto the cartridgebody 10. The other disc holding portions 21 a, 21 b and 22 b also havetheir own sloped portions 21 a′, 21 b′ and 22 b′, respectively. Thus,just like the sloped portion 22 a′, these sloped portions 21 a′, 21 b′and 22 b′ also hold and fix the disc 100 onto the cartridge body 10.

In this state, the signal recording side 100A of the disc 100 is inclose contact with the sheets 21 p and 22 p. Thus, no dust will bedeposited on the signal recording side 100A. Also, if the exposed sideof the disc 100 is rotated manually or if the shutters 21 and 22 areopened or closed intentionally, then dust, finger marks or any otherdirt that has adhered onto the signal recording side 100A of the disc100 may be wiped away.

Furthermore, since the shutters 21 and 22 are locked by the lockingmechanism 20 k, the operator cannot open the shutters 21 and 22accidentally. Thus, the signal recording side 100A of the disc 100 canbe protected from dust, finger marks or scratches.

Furthermore, the hole 20 h, which is defined by the notches 21 h and 22h provided for the shutters 21 and 22, respectively, is provided in theregions of the shutters 21 and 22 that are located under the center hole100 h of the disc 100. In such a structure, even if the cartridge 313 isleft, dust may pass through the center hole 100 h but will not bedeposited on the shutters 21 and 22.

Also, while the shutters 21 and 22 are closed, at least the two pairs ofcontact surfaces 21 f, 22 f and 21 g, 22 g of the shutters 21 and 22,which are butted with each other over the head and chucking openings 11h and 11 c, each overlap with each other in the thickness direction ofthe disc 100 as shown in FIGS. 70 and 71. Accordingly, even if theshutters 21 and 22 have been closed incompletely because a disc 100having a non-regular diameter has been mounted or because the shutters21 and 22 have not been locked completely, no gap will be createdbetween the contact surfaces of the shutters 21 and 22. Thus, even insuch a situation, the disc 100 can also be protected from dust, fingermarks or scratches.

Also, as shown in FIG. 70, the shutters 21 and 22 are in contact witheach other around the head opening 11 h so that the contact surface 22 gof the shutter 22 is located over the contact surface 21 g of theshutter 21. On the other hand, as shown in FIG. 71, the shutters 21 and22 are in contact with each other around the chucking opening 11 c sothat the contact surface 21 f of the shutter 21 is located over thecontact surface 22 f of the shutter 22. In this manner, the angledefined by one of multiple contact surfaces of the shutter 21 or 22 maybe different from the angle defined by another one of the contactsurfaces of the shutter 21 or 22. In such a structure, the two shutters21 and 22 can be tightly engaged with each other in the thicknessdirection of the disc. Thus, neither the shutter 21 nor the shutter 22will be raised unintentionally. In addition, while the shutters 21 and22 are closed, the contact surfaces of the shutters 21 and 22 can haveincreased rigidity.

In this embodiment, the shutters 21 and 22 have the contact surfaces 21g, 22 g, 21 f and 22 g shown in FIGS. 70 and 71. However, the shutters21 and 22 may also have contact surfaces at different locations or maycontact with each other in a different manner from those shown in FIGS.70 and 71. For example, the contact surfaces 21 g and 22 g shown in FIG.70 may be shifted to a location around the head opening 11 h and contactwith each other. Alternatively, the contact surfaces 21 f and 22 f shownin FIG. 71 may be shifted to a location around the chucking opening 11 cand contact with each other. Then, the shutters 21 and 22 can exhibiteven higher rigidity when closed, and the gap between the contactsurfaces can be further reduced, thus preventing any dust from enteringthe inside of the cartridge.

Also, while the shutters 21 and 22 are closed, convex portions 21 j and22 j, provided for the shutters 21 and 22 as shown in FIG. 68, are incontact with two shutter stopper portions 12 f provided for thecartridge upper shell 12 as shown in FIG. 65. Accordingly, the shutters21 and 22 have its rotation regulated and cannot move from their lockedpositions. As a result, the shutters will not move inconstantly. Inaddition, it is possible to prevent the operator from breaking theshutters intentionally. Furthermore, since the shutters 21 and 22 havetheir rotation regulated, the shutter opening/closing portion 22 t isnot displaced. Accordingly, when this disc cartridge 313 is loaded intoa disc drive, the shutter opening/closing portion 22 t can be engagedwith the shutter opening/closing mechanism of the disc drive just asintended.

Next, it will be described how this disc cartridge 313 is loaded intothe disc drive. As shown in FIG. 66, when the disc cartridge 313 isinserted into the disc drive in the direction 1A, the cartridgepositioning pins of the disc drive engage with the positioning holes 11w of the disc cartridge 313, thereby determining the horizontal andvertical positions of the disc cartridge 313 inside the disc drive.

Then, a shutter opening/closing member of the shutter opening/closingmechanism provided inside the disc drive engages with the shutteropening/closing portion 22 t shown in FIG. 68. At the same time, anunlocking member of the shutter opening/closing mechanism presses alocking press portion 21 y, which is connected to the shutter 21 by wayof a locking elastic portion 21 e, in the direction 20A. As a result,the locking protrusion portion 21 k of the locking mechanism 20 k isdisengaged from the locking engaging portion 22 k thereof, therebyunlocking the shutters 21 and 22 from each other. In such a state, theshutter opening/closing member moves the shutter opening/closing portion22 t in the direction 20B at the same time. Consequently, the shutter 21rotates on the rotation shaft 11 s while overcoming the elastic forceapplied from the shutter spring 31 as shown in FIG. 67. Synchronously,the other shutter 22, which is interlocked with the shutter 21 via theinterlocking mechanism 20 c, also rotates while overcoming the elasticforce applied from the shutter spring 32. Accordingly, when the shutter21 has been opened, the shutter 22 will have also been opened.

By this point in time, the locking protrusion portion 21 k and thelocking press portion 21 y will have recovered their original shapes andreturned to their home positions along with the locking elastic portion21 e. Thus, the locking elastic portion 21 e made of a resin is notdeformed plastically. In this manner, the signal recording side 100A ofthe disc 100 is exposed through the chucking and head openings 11 c and11 h. Also, the disc 100, which has been held by the disc holdingportions 21 a, 21 b, 22 a and 22 b, is released therefrom as theshutters 21 and 22 rotate. As a result, the disc 100 is now freelyrotatable inside the disc storage portion 10 d.

Subsequently, the spindle motor and the turntable of the disc driveenter the chucking opening 11 c and the head thereof enters the headopening 11 h. Consequently, the disc drive is now ready to perform awrite or read operation on the disc 100.

As described above, only by getting the locking protrusion portion 21 kpressed externally by a protrusion, for example, in the direction 20Aand disengaged from the locking engaging portion 22 k while pressing theshutter opening/closing portion 22 t in the direction indicated by thearrow 20B at the same time, the shutters 21 and 22 can be rotated toexpose the chucking and head openings 11 c and 11 h and the disc 100 canbe released from the disc holding portions 21 a, 21 b, 22 a and 22 b.Thus, it is possible to prevent the operator from opening the shuttersor removing the disc accidentally. As a result, the disc 100 can beprotected from dust, finger marks or scratches.

Hereinafter, it will be described how the disc cartridge 313 is ejectedfrom the disc drive. When an ejecting mechanism of the disc drive startsto operate, the shutter opening/closing member, which has been engagedwith the shutter opening/closing portion 22 t, disengages itself fromthe shutter opening/closing portion 22 t. As a result, the shutters 21and 22 cannot be kept opened anymore. That is to say, the shutters 21and 22, to which an elastic force is being applied from the shuttersprings 31 and 32 in such a direction as to close the shutters 21 and22, start to rotate in the closing direction. Consequently, the shutters21 and 22 close up the head and chucking openings 11 h and 11 c. In thiscase, the shutters 21 and 22 are locked to each other by the lockingmechanism 20 k. In the meantime, the disc 100 gets held by the discholding portions 21 a, 21 b, 22 a and 22 b again to recover its originalstate. In such a state, the disc cartridge 313 is ejected from the discdrive.

In the disc cartridge 313, the disc contact portion 23 a of the stoppermembers 23 provided for the cartridge body 10 and the disc contactportion 12 s′ of the cartridge upper shell 12 are located at the samevertical level as shown in FIG. 69. Also, the top of the sloped portions21 a′, 21 b′, 22 a′ and 22 b′ of the disc holding portions 21 a, 21 b,22 a and 22 b of the shutters 21 and 22 is higher in level than thebottom of the disc contact portions 23 a and 12 s′ in the direction 100u in which the disc 100 is moved upward. Accordingly, although the disccartridge 313 may be used either vertically or upside down depending onthe type of the disk drive, the shutters 21 and 22 still can hold thedisc 100 firmly thereon. For example, particularly when the disc 100 isused upside down, the disc 100 that is no longer chucked contacts withthe disc contact portions 23 a and 12 s′ and still can maintain itshorizontal position. And when the shutters 21 and 22 are closed in sucha state, the disc 100 contacts with the slopes 21 a′, 21 b′, 22 a′ and22 b′ this time. Then, the disc 100 will slide along the slopes smoothlyto be held firmly by the disc holding portions 21 a, 21 b, 22 a and 22b.

As described above, in the disc cartridge of this embodiment, thecartridge body thereof has a disc window and covers only one side of thedisc. Also, a shutter opening/closing portion is provided inside a headopening of the cartridge body, and therefore, there is no need toprovide any unnecessary gap for the cartridge body. As a result, no dustwill enter the inside of the cartridge body.

In addition, the two shutters are made to contact with each other alongthe centerline of the disc over the chucking opening and along a line,which defines a predetermined angle with the centerline of the disc,over the head opening. Accordingly, these shutters can have anintegrated structure from the vicinity of the shutter opening/closingportion and can exhibit sufficiently high rigidity.

Furthermore, since the two shutters are locked or unlocked to/from eachother, the operator cannot open or close the shutters accidentally.Thus, the disc can be protected from dust, finger marks or scratches.

Moreover, at least one of multiple disc holding portions is not securedto the shutter but is just connected thereto via an elastic portion. Asan elastic force is also applied from a shutter spring, the disc holdingportion can be deformed elastically in the disc radial direction. Forthat reason, even if a disc of a non-regular diameter has been mounted,such a disc can also be held firmly without allowing it to moveinconstantly.

Embodiment 14

Hereinafter, a disc cartridge 314 according to a fourteenth embodimentof the present invention will be described with reference to FIGS. 72through 81. In the disc cartridge 314 of this embodiment, the samemember as the counterpart of the disc cartridge 313 of the thirteenthembodiment is identified by the same reference numeral.

The disc cartridge 314 is different from the disc cartridge 313 of thethirteenth embodiment in the respective shapes of the inner uppersurface 12 u of the cartridge upper shell 12 (see FIG. 79), the discholding portions 21 a, 21 b, 22 a and 22 b (see FIGS. 72 through 79) andthe stopper members 53 (see FIGS. 72, 77 and 78). In addition, the disccartridge 314 further includes a disc receiving portion 60 (see FIGS. 72and 81). Thus, the following description of the disc cartridge 314 willbe focused on these differences.

In the disc cartridge 313 of the thirteenth embodiment, the respectivetops of the disc holding portions 21 a, 21 b, 22 a and 22 b thereof arelocated at substantially the same vertical levels along the outerperiphery of the disc 100. In contrast, in the disc cartridge 314 ofthis embodiment, protrusions are formed on the disc holding portions 21b, 22 a and 22 b as shown in FIGS. 73 and 79. More specifically, each ofthe disc holding portions 21 b, 22 a and 22 b includes: a first portion121 b, 122 a or 122 b that has a protrusion thereon and has a firstheight h1; and a second portion 221 b, 222 a or 222 b that has a secondheight h2. The other disc holding portion 21 a consists of a secondportion 221 a that has the second height h2.

The first height h1 is greater than the second height h2 and isapproximately equal to the height of the disc holding portions 21 a, 21b, 22 a and 22 b of the disc cartridge 313 of the thirteenth embodiment.That is to say, the disc holding portions 21 a, 21 b, 22 a and 22 b ofthis embodiment are lower than the disc holding portions 21 a, 21 b, 22a and 22 b of the disc cartridge 313 of the thirteenth embodiment excepttheir first portions 121 b, 122 a and 122 b.

Also, as shown in FIGS. 74 and 75, a step 223 is formed on the uppersurface of the first portion 122 a of the disc holding portion 22 a.Specifically, the step 223 is provided along the outer periphery of thedisc so that a part of the first portion 122 a that is closer to thedisc is higher than the other part thereof. A similar step is alsoformed on the upper surface of the first portion 121 b of the discholding portion 21 b and on the upper surface of the first portion 122 bof the disc holding portion 22 b.

As the shutters 21 and 22 are going to be closed, the first portion 121b, 122 a or 122 b of the disc holding portion 21 b, 22 a or 22 bcontacts with the disc 100 earlier than any other portion thereof (i.e.,earlier than the second portion 221 b, 222 a or 222 b thereof).

The disc holding portions 21 a, 21 b, 22 a and 22 b move as the shutters21 and 22 are opened or closed. FIG. 77 illustrates the respectivepositions of the disc holding portions 21 a, 21 b, 22 a and 22 b whilethe shutters 21 and 22 are closed. On the other hand, FIG. 78illustrates the respective positions of the disc holding portions 21 a,21 b, 22 a and 22 b while the shutters 21 and 22 are opened. FIGS. 79and 80 illustrate cross sections that are respectively taken along thelines B—B and C—C shown in FIG. 78.

As shown in FIGS. 77, 78 and 79, the regions 12 y, 12 x and 12 z on theinner upper surface 12 u of the cartridge upper shell 12, through whichthe first portions 121 b, 122 a and 122 b of the disc holding portions21 b, 22 a and 22 b pass as the shutters 21 and 22 are opened or closed,are recessed. On the other hand, the regions 12 y′, 12 x′ and 12 z′,through which the second portions 221 b, 222 a and 222 b thereof pass,are not recessed. Accordingly, the cartridge upper shell 12 is thinnerin the regions 12 x, 12 y and 12 z than in the regions 12 x′, 12 y′ and12 z′ and the other regions.

As shown in FIGS. 76 and 79, the top of the first portion 122 a islocated at a vertical level higher than the bottom of the stopper member53. Also, the top of the first portion 122 a of the disc holding portion22 a enters the recessed region 12 x on the inner upper surface 12 u ofthe cartridge upper shell 12, and the recessed region 12 x receives thetop of the first portion 122 a. Since the step 223 is formed at the topof the first portion 122 a, just a part of the upper surface of thefirst portion 122 a is in contact with the inner upper surface 12 u. Onthe other hand, the second portion 222 a is not in contact with theinner upper surface 12 u of the cartridge upper shell 12.

To open and close the shutters 21 and 22 smoothly, the friction causedby the contact between the top of the first portion 122 a of the discholding portion 22 a and the inner upper surface 12 u of the cartridgeupper shell 12 is preferably small. For that purpose, the top of thefirst portion 122 a of the disc holding portion 22 a has a convexarc-shaped cross section when taken in the radial direction of the disc100. This step 223 is provided to compensate for shortage in strength,which would be caused by a sharpened top, and to make that top moldablemore accurately and more easily.

As shown in FIG. 80, the top of the first portion 122 b of the discholding portion 22 b is also located at a vertical level higher than thebottom of the stopper member 53. And the top of the first portion 122 benters the recessed region 12 z on the inner upper surface 12 u of thecartridge upper shell 12 (i.e., the recessed region 12 z receives thetop of the first portion 122 b). Although not shown, the top of thefirst portion 121 b of the disc holding portion 21 b is also located ata vertical level higher than the bottom of the stopper member 53, andenters the recessed region 12 y on the inner upper surface 12 u of thecartridge upper shell 12.

As described above, the regions 12 x, 12 y and 12 z on the inner uppersurface 12 u of the cartridge upper shell 12 are recessed to receiveportions of the disc holding portions. Thus, the overall thickness ofthe disc cartridge 314 can be reduced by the depth of those recessedregions 12 x, 12 y and 12 z.

Even if the cartridge having such a structure is used either verticallyor upside down, the disc 100 that is no longer chucked never fails tocontact with the sloped portion 122 a′ of the first portion 122 a of thedisc holding portion 22 a as the shutters 21 and 22 are going to beclosed. Thereafter, the disc 100 will slide smoothly along the slopedportion 122 a′ to contact with the sloped portion 222 a′ of the secondportion 222 a of the disc holding portion 22 a (see FIG. 74). At thesame time, the disc 100 also contacts with the sloped portion 221 a′ ofthe second portion 221 a of the disc holding portion 21 a including noprotrusion. In this manner, the disc holding portions 21 a and 22 a holdthe disc 100 thereon cooperatively. The two other disc holding portions21 b and 22 b also hold the disc 100 thereon through similar operations.Accordingly, although this disc cartridge has a reduced thickness, thedisc cartridge can close the shutters in any position and can hold thedisc thereon just as intended.

If this disc cartridge had its overall thickness just reduced withoutchanging the shapes of the disc holding portions (or using the discholding portions of the first embodiment as they are), the regions 12 x,12 x′, 12 y, 12 y′, 12 z and 12 z′ on the inner upper surface 12 u ofthe cartridge upper shell 12, through which the disc holding portions 22a, 21 b and 22 b pass, should all be recessed as can be seen from FIG.78. In that case, the cartridge upper shell 12 would have a reducedthickness over a rather wide area and such a disc cartridge would have adecreased strength. In contrast, the disc cartridge 314 can have itsthickness reduced without decreasing its overall strength because theregions 12 x, 12 y and 12 z with a reduced thickness are relativelynarrow.

In this embodiment, protrusions are provided for three of the four discholding portions to define the first portions. However, any other numbermay be selected depending on the number of disc holding portions or theshapes of the shutters.

The disc cartridge 314 of this embodiment is also different from thedisc cartridge 313 of the thirteenth embodiment in the shape of thestopper members 53.

As shown in FIG. 72, the stopper members 53 have the shape of a notchedcircular plate. Specifically, notches 54 having substantially the sameshape as the stopper members 53 are provided along the disc window 12 wof the cartridge upper shell 12 and the stopper members 53 are engagedin a rotatable state with the notches 54. As shown in FIG. 77, thestopper members 53 are held in such a manner as to partially protrudeinto the disc window 12 w of the cartridge upper shell 12 when rotated.Also, as shown in FIG. 78, by rotating the stopper members 53, thestopper members 53 may also be held in such a manner as to be storedinside the cartridge upper shell and not to protrude into the discwindow 12 w. If the stopper members 53 are easily disengaged from thenotches 54 unintentionally, then the side surfaces of the stoppermembers 53 and the notches 54 of the cartridge upper shell 12 may havemutually engaging concave and convex portions, for example.

In such a structure, the thickness of the stopper members 53 may besubstantially equal to that of the upper part of the cartridge uppershell 12. Thus, the disc cartridge 314 can have a reduced overallthickness.

The disc cartridge 314 of this embodiment is also characterized byincluding a disc receiving portion 60 at the bottom of the innerperiphery of the disc storage portion. The disc storage portion isdefined by the inner lower surface 11 u and the inner side surface 11 i.of the cartridge lower shell 11 as shown in FIGS. 72, 77, 78 and 81. Thedisc receiving portion 60 has an upper surface 60 a, which is parallelto the inner lower surface 11 u of the cartridge lower shell 11.

While the shutters 21 and 22 are closed and the disc 100 is held by thedisc holding portions, the outer edge and its surrounding portion of thesignal recording side 100A of the disc 100 are in contact with the uppersurface 60 a of the disc receiving portion 60. Thus, no dust will bedeposited on the signal recording side 100A of the disc 100 oraccumulated on the inner lower surface 11 of the cartridge lower shell.

Alternatively, the disc receiving portion 60 may have any shape otherthan that shown in FIG. 81. For example, as shown in FIG. 82, a discreceiving portion 76 having a tapered shape may be formed so as tocontact with the inner lower surface 11 u and the inner side surface 11i of the cartridge lower shell. In that case, while the shutters 21 and22 are closed and the disc 100 is held by the disc holding portions, theouter edge of the signal recording side 100A of the disc 100 contactswith the disc receiving portion 76.

Embodiment 15

Hereinafter, a disc cartridge 315 according to a fifteenth embodiment ofthe present invention will be described with reference to FIGS. 83through 87. In the disc cartridge 315 of this embodiment, the samemember as the counterpart of the disc cartridge 314 of the fourteenthembodiment is identified by the same reference numeral.

As shown in FIG. 83, the disc cartridge 315 is different from the disccartridge 314 in that the disc cartridge 315 includes four types ofrecesses 85, 86, 87 and 88 a through 88 c on respective regions of theinner lower surface 11 u of the cartridge lower shell 11 that contactwith the shutters 21 and 22 and on the lower surfaces 21 v and 22 v ofthe shutters 21 and 22. These four types of recesses will be describedone by one. Where the disc cartridge is supposed to hold a 12 cm disc,these recesses may have a depth of about 0.1 mm to about 0.3 mm, forexample.

As can be seen from FIGS. 84 and 85 illustrating a state where theshutters 21 and 22 are closed and a state where the shutters 21 and 22are opened, respectively, the first type of recesses 86 are formed onrespective regions of the inner lower surface 11 u of the cartridgelower shell 11 that contact with the disc holding portions 21 a, 21 b,22 a and 22 b of the shutters 21 and 22 being opened or closed.

The disc holding portions 21 a, 21 b, 22 a and 22 b are sandwichedbetween the cartridge upper and lower shells 12 and 11 with almost nogap left between them. Accordingly, when respective members of the disccartridge 315 are assembled together or if any of those members of thedisc cartridge 315 has a size that is greatly different from thedesigned one, the disc holding portions 21 a, 21 b, 22 a and 22 b mightcontact with the cartridge upper and lower shells 12 and 11 strongly. Inthat case, excessive friction would be created between the disc holdingportions 21 a, 21 b, 22 a and 22 b and the cartridge upper or lowershell 12 or 11. As a result, the shutters 21 and 22 might be unable tobe opened or closed so easily or dust might be stirred up due to thefriction.

However, by providing the first type of recesses 86, gaps are providedunder the disc holding portions 21 a, 21 b, 22 a and 22 b, thus reducingsuch friction. Then, the shutters 21 and 22 can always be opened orclosed smoothly and the dust to be stirred up due to the friction can bereduced.

The second type of recesses 87 are formed on those regions where therespective outer edges of the shutters 21 and 22 are located while theshutters 21 and 22 are closed. As shown in FIGS. 84 and 86, the secondtype of recesses 87 preferably include the lines on the inner lowersurface 11 u of the cartridge lower shell 11 that correspond to theouter edges of the shutters 21 and 22 and are preferably present bothinside and outside the lines.

The disc cartridge 315 is supposed to store the disc therein with oneside thereof exposed, and the disc 100 can be pressed in the directionindicated by the arrow A in FIG. 86. To protect the signal recordingside 100A of the disc 100, the nonwoven fabrics 21 s and 22 s areprovided but the outer edges of the shutters 21 and 22 are notcompletely covered with the nonwoven fabrics 21 s and 22 s. Accordingly,if the disc 100 is pressed in the arrowed direction A, then the outeredges of the shutters 21 and 22 contact with the signal recording side100A of the disc 100, thus possibly scratching the signal recording side100A.

However, if the second type of recesses 87 are provided, the shutters 21and 22 may be deformed in such a manner that the outer edges thereof arepartially forced into the second type of recesses 87. Then, the pressingforce can be dispersed, and the outer edges of the shutters 21 and 22will not contact with the signal recording side 100A of the disc 100 toostrongly.

The third type of recesses include: the third type of recesses 88 a thatare provided on the inner lower surface 11 u so as to surround thechucking and head openings 11 c and 11 h; the third types of recesses 88b that are formed on those regions of the inner lower surface 11 u thatare not overlapped by the shutters 21 and 22 being closed; and the thirdtype of recess 88 c that is provided on a region of the inner lowersurface 11 u that is overlapped by the shutters 21 and 22 being closed.The third type of recesses 88 b and 88 c are provided as arcs along theinner side surface of the disc storage portion. In this embodiment, thenumber of the recesses 88 a of the third type is three.

This disc cartridge 315 is also provided with various types ofstructures (e.g., a disc receiving portion) for preventing dust fromentering the disc cartridge or being deposited on the signal recordingside of the disc. However, it is difficult to totally eliminate thatentering or deposition of dust.

Thus, the third type of recesses are provided to accumulate the dustthat has entered the disc cartridge 315. Specifically, as the shutters21 and 22 are going to be opened or closed, the dust is collected inthese recesses of the third type. Once collected in the third type ofrecesses, the dust never contacts with the shutters 21 and 22 andremains in the third type of recesses without going out of the thirdtype of recesses. Accordingly, by accumulating the dust in the thirdtype of recesses in this manner, the dust will not interfere with theoperation of the shutters or will be stirred up to a much lesser degreedue to the friction.

It should be noted that these effects are also achievable by the firsttype of recesses 86 or the second type of recesses 87. Accordingly, thedisc cartridge 315 does not have to include all of the first, second andthird types of recesses 86, 87, 88 a, 88 b and 88 c but may include justone type of recesses. Even so, the shutters will not be interfered withtheir operation by the dust and almost no dust will be stirred up due tothe friction to say the least.

Also, to remove the dust that has entered the gap between the shutters21 and 22 and the inner lower surface 11 u of the cartridge lower shell11 and accumulate it in the second type of recesses 87, for example,even more effectively, the respective lower surfaces 21 v and 22 v ofthe shutters 21 and 22 may be provided with the recesses 85 along theouter edges thereof. In that case, when the shutters 21 and 22 areclosed, these recesses 85 are preferably located inside the second typeof recesses 87 (i.e., closer to the center of the cartridge) as shown inFIG. 84. Also, as shown in FIG. 86, while the shutters 21 and 22 areclosed, the recesses 85 of the shutters 21 and 22 are preferablydiscontinuous from the second type of recesses 87 on the inner lowersurface 11 u of the cartridge lower shell 11.

When the recesses 85 are provided, the outer edge portions of theshutters 21 and 22 are deformed more easily. Accordingly, even when aforce is externally applied to the disc 100 in the arrowed direction A,the outer edge portions of the shutters 21 and 22 will much less likelycontact with the signal recording side 100A so strongly as to scratchit. Optionally, a nonwoven fabric, for example, may be welded or adheredto these recesses 86, 87, 88 a, 88 b and 88 c. Then, the gaps of thecartridge body can be filled and entering of extraneous dust can beprevented with even more certainty.

In this embodiment, the various types of recesses are provided for thedisc cartridge 314 of the fourteenth embodiment. Alternatively, theserecesses may also be provided for the disc cartridge according to any ofthe eighth through thirteenth embodiments.

Embodiment 16

Hereinafter, a disc cartridge 316 according to a sixteenth embodiment ofthe present invention will be described with reference to FIGS. 88through 93. In the disc cartridge 316 of this embodiment, the samemember as the counterpart of the disc cartridge 313 of the thirteenthembodiment is identified by the same reference numeral.

As shown in FIG. 88, the disc cartridge 316 of this embodiment includes:a first opening/closing portion 22 t on a first side surface 10 p of thecartridge body that extends substantially vertically to the direction 1Ain which this disc is inserted; and a second opening/closing portion 93on a second side surface 10 q thereof. The first opening/closing portion22 t has the same structure as the opening/closing portion 22 t of thedisc cartridge of the thirteenth embodiment.

As shown in FIG. 89, the second opening/closing portion 93 is formed inthe shape of a gear having a hole that can be inserted into a rotationshaft 11 q provided for the cartridge lower shell 11. A side surface ofthe cartridge lower shell 11 has an opening 11 r to expose a portion ofthe second opening/closing portion 93 through the second side surface 10q of the cartridge body 10 when the second opening/closing portion 93 isinserted into the rotation shaft 11 q. Alternatively, the rotation shaft11 q may be provided for the cartridge upper shell 12.

Two shutters 21 and 22 are also provided to expose or cover the head andchucking openings 11 h and 11 c of the cartridge lower shell 11. Thefirst opening/closing portion 22 t forms an integral part of the shutter22 (i.e., the first shutter member). On the other hand, a sector gear 21m, which engages with the second opening/closing portion 93 having thegear shape, is formed on the outer side surface of the shutter 21 (i.e.,the second shutter member) and is located near the disc holding portion21 b. The center of the sector gear 21 m is the rotation hole 21 u ofthe shutter 21. A concave portion 21 n is provided adjacent to thesector gear 21 m. This concave portion 21 n is formed to define a spacein which the second opening/closing portion 93 having the gear shapeengages with the sector gear 21 m.

The shutters 21 and 22 may be opened or closed by using the firstopening/closing portion 22 t in the following manner. First, as shown inFIG. 90, the locking protrusion portion 21 k and the locking engagingportion 22 k, which together make up the locking mechanism 20 k, aredisengaged from each other. Then, the first opening/closing portion 22 tis slid along the first side surface 10 p of the cartridge as indicatedby the arrow 22W. As a result, the movement of the shutter 22 istransmitted to the shutter 21 by way of the interlocking mechanism 20 cand these two shutters 21 and 22 expose the head and chucking openings11 h and 11 c cooperatively as shown in FIG. 91.

The shutters 21 and 22 may also be opened or closed by using the secondopening/closing portion 93 in the following manner. First, the lockingmechanism 20 k is unlocked as shown in FIG. 90. Next, the secondopening/closing portion 93 is rotated to the direction indicated by thearrow 93A. Then, the sector gear 21 m gets engaged with the gearedsecond opening/closing portion 93 and starts to rotate around therotation hole 21 u, thereby opening the shutter 21. Since the movementof the shutter 21 is transmitted to the shutter 22 by way of theinterlocking mechanism 20 c and these two shutters 21 and 22 expose thehead and chucking openings 11 h and 11 c cooperatively. When the headand chucking openings 11 h and 11 c are completely exposed by theshutters 21 and 22 as shown in FIG. 91, a portion of the secondopening/closing portion 93 is located inside the concave portion 21 n ofthe shutter 21.

In closing the shutters 21 and 22, the first opening/closing portion 22t may be slid in the direction opposite to the direction 22W or thesecond opening/closing portion 93 may be rotated to the directionopposite to the direction 93A. In this embodiment, the shutter springs31 and 32 are provided to apply an elastic force to the shutters 21 and22 in such a direction as to close the shutters 21 and 22. Accordingly,unless a force that is strong enough to open, or keep opened, theshutters 21 and 22 against the elastic force of the shutter springs 31and 32 is applied to the first or second opening/closing portion 22 t or93, the shutters 21 and 22 close themselves automatically even withoutperforming the operations described above.

In the disc cartridge 316 of this embodiment, the opening/closingportions are provided for the shutters 21 and 22 both on a surface thatis perpendicular to the disc inserting direction and on a surface thatis parallel to the disc inserting direction. Accordingly, no matterwhether the disc drive used is compatible with only a disc cartridgeincluding a shutter opening/closing portion on a side surface thatextends perpendicularly to the disc cartridge inserting direction oronly a disc cartridge including a shutter opening/closing portion on aside surface that extends parallelly to the disc cartridge insertingdirection, the disc drive can always write or read a signal on/from thedisc in the disc cartridge of this embodiment.

Also, in the disc cartridge 316 of this embodiment, the secondopening/closing portion 93, provided for the side surface parallel tothe direction in which the disc cartridge 316 is inserted, has a gearshape. Accordingly, a shutter opening/closing mechanism to be providedfor the disc drive may also be any of various shapes of gears that canengage with the second opening/closing portion 93. Thus, the disc drivemay use a relatively simple mechanism to open or close the shutters 21and 22 of the disc cartridge 316.

In the embodiment described above, the sector gear 21 m is provided nearthe disc holding portion 21 b. This is because the distance between thesector gear 21 m at such a position and the rotation hole 21 u of theshutter 21 is relatively short and because the sector gear 21 m needs tohave a relatively short length to open the shutter 21 fully. However,the sector gear 21 m does not have to be provided at this position.Alternatively, the sector gear 21 m and the second opening/closingportion 93 may also be provided at such positions as shown in FIGS. 92and 93. In FIGS. 92 and 93, the sector gear 21 m is located at such aposition that when extended, a circular trace drawn by the sector gear21 m will substantially intersect with the center of the disc, while thesecond opening/closing portion 93 is provided at such a position as toengage with the sector gear 21 m. When the second opening/closingportion 93 is provided at such a position, the sector gear 21 m shouldbe relatively long to open the shutter 21 fully, but the distancebetween the sector gear 21 m and the rotation hole 21 u may also berelatively long. That is to say, since there is a longer distancebetween the fulcrum and the application point in that case, a lighterforce is needed to rotate the second opening/closing portion 93 and openor close the shutters 21 and 22.

Embodiment 17

Hereinafter, a disc cartridge 317 according to a seventeenth embodimentof the present invention will be described with reference to FIGS. 94through 97. In the disc cartridge 317 of this embodiment, the samemember as the counterpart of the disc cartridge 316 of the sixteenthembodiment is identified by the same reference numeral.

As shown in FIG. 94, the disc cartridge 317 of this embodiment includesa second opening/closing portion 94 on its second side surface 10 qinstead of the second opening/closing portion 93 of the disc cartridge316 of the sixteenth embodiment.

As can be seen from FIG. 95, the second opening/closing portion 94 is alink member that can slide along the opening 11 r on the side surface ofthe cartridge lower shell 11 and is bent approximately at the centerthereof. Also, the second opening/closing portion 94 includes aprotrusion 94 a at one end thereof. This protrusion 94 a engages with agroove 21 i that is provided on the shutter 21 near the disc holdingportion 21 b thereof.

FIGS. 96 and 97 illustrate two states of the disc cartridge 317 in whichthe shutters 21 and 22 thereof are closed and opened, respectively. Asalready described for the thirteenth and sixteenth embodiments, theshutters 21 and 22 can be opened or closed by sliding the firstopening/closing portion 22 t in the direction indicated by the arrow 22w.

The shutters 21 and 22 may also be opened or closed by using the secondopening/closing portion 94 in the following manner. First, the lockingmechanism 20 k is unlocked as shown in FIG. 96. Next, the secondopening/closing portion 94 is slid in the direction indicated by thearrow 94B. As a result of this operation, a force is applied to thesecond opening/closing portion 94 in such a direction as to move theprotrusion 94 a of the second opening/closing portion 94 in thedirection indicated by the arrow 94B. Thus, the shutter 21 is rotatedaround the rotation hole 21 u and opened. Since the movement of theshutter 21 is transmitted to the shutter 22 by way of the interlockingmechanism 20 c, these two shutters 21 and 22 expose the head andchucking openings 11 h and 11 c cooperatively. As in the sixteenthembodiment, the shutters 21 and 22 can also be closed by sliding thesecond opening/closing portion 94 in the direction opposite to thedirection 94B, and the shutter springs 31 and 32 also apply an elasticforce to the shutters 21 and 22 in the same direction.

Just like the disc cartridge of the sixteenth embodiment, no matterwhether the disc drive used is compatible with only a disc cartridgeincluding a shutter opening/closing portion on a side surface thatextends perpendicularly to the disc cartridge inserting direction oronly a disc cartridge including a shutter opening/closing portion on aside surface that extends parallelly to the disc cartridge insertingdirection, the disc drive can always write or read a signal on/from thedisc in the disc cartridge of this embodiment.

Also, as shown in FIGS. 96 and 97, the direction 94B in which the secondopening/closing portion 94 is slid to open the shutters 21 and 22 isantiparallel to the disc cartridge inserting direction 1A. Accordingly,if a protrusion that engages with the second opening/closing portion 94is provided for a disc drive, that protrusion engages with the secondopening/closing portion 94 and opens the shutters 21 and 22 of the disccartridge while the disc cartridge of this embodiment is going to beinserted into the disc drive. Thus, a simplified shutter opening/closingmechanism may be provided for the disc drive.

Embodiment 18

Hereinafter, a disc cartridge 318 according to an eighteenth embodimentof the present invention will be described with reference to FIGS. 98through 101. In the disc cartridge 318 of this embodiment, the samemember as the counterpart of the disc cartridge 316 of the sixteenthembodiment is identified by the same reference numeral.

As shown in FIG. 98, the disc cartridge 318 of this embodiment includesa second opening/closing portion 96 on its second side surface 10 qinstead of the second opening/closing portion 93 of the disc cartridge316 of the sixteenth embodiment.

As can be seen from FIG. 99, the second opening/closing portion 96 is abelt member that is connected to the disc holding portion 21 a of theshutter 21. This belt member has a protrusion 96 a at one end thereof.And the protrusion 96 a can slide along the opening 11 r on the sidesurface of the cartridge lower shell 11. Alternatively, the secondopening/closing portion 96 may form an integral part of the shutter 21.

FIGS. 100 and 101 illustrate two states of the disc cartridge 318 inwhich the shutters 21 and 22 thereof are closed and opened,respectively. As already described for the sixteenth and seventeenthembodiments, the shutters 21 and 22 can be opened or closed by slidingthe first opening/closing portion 22 t in the direction indicated by thearrow 22 w.

The shutters 21 and 22 may also be opened or closed by using the secondopening/closing portion 96 in the following manner. First, the lockingmechanism 20 k is unlocked as shown in FIG. 100. Next, the protrusion 96a of the second opening/closing portion 96 is slid in the directionindicated by the arrow 96B. As a result of this operation, a force isapplied to the shutter 21 in such a direction as to rotate the shutter21 on the rotation hole 21 u and pull the end of the shutter 21 to thedirection indicated by the arrow 96C. Since the movement of the shutter21 is transmitted to the shutter 22 by way of the interlocking mechanism20 c, these two shutters 21 and 22 expose the head and chucking openings11 h and 11 c cooperatively. To close the shutters 21 and 22, theopposite operation is performed.

Just like the disc cartridge of the sixteenth embodiment describedabove, no matter whether the disc drive used is compatible with only adisc cartridge including a shutter opening/closing portion on a sidesurface that extends perpendicularly to the disc cartridge insertingdirection or only a disc cartridge including a shutter opening/closingportion on a side surface that extends parallelly to the disc cartridgeinserting direction, the disc drive can always write or read a signalon/from the disc cartridge of this embodiment.

If the second opening/closing portion 96 forms an integral part of theshutter 21, the number of members that make up the disc cartridge can bereduced. As a result, the manufacturing cost of the disc cartridge canbe reduced or the manufacturing process thereof can be simplified.

In the sixteenth through eighteenth embodiments described above, thesecond opening/closing portion is provided on the left-hand side withrespect to the disc cartridge inserting direction. However, the locationof the second opening/closing portion is not limited to the left-handside described above. Alternatively, the second opening/closing portionmay be provided on the right-hand side 10 r with respect to the discinserting direction as shown in FIG. 88. As another alternative, thesecond opening/closing portion may also be provided on the back surface10 t of the disc cartridge as shown in FIG. 88. In that case, thebelt-shaped second opening/closing portion 96 of this eighteenthembodiment is preferably used because the disc cartridge can have thesecond opening/closing portion on its back surface without changing itsdetails so much.

Embodiment 19

Hereinafter, a disc cartridge 319 according to a nineteenth embodimentof the present invention will be described with reference to FIGS. 102and 103. In the disc cartridge 319 of this embodiment, the same memberas the counterpart of the disc cartridge 313 of the thirteenthembodiment is identified by the same reference numeral.

The disc cartridge 319 of this embodiment is characterized by providingrotation stopper members 97 for the disc holding portions 21 b, 22 a and22 b and concave portions 89 for the shutters 21 and 22, respectively.The concave portions 89 are used to ultrasonic weld a nonwoven fabric tothe shutters 21 and 22.

More specifically, the disc holding portions 21 b, 22 a and 22 b includeholes 21 q, 22 r and 22 q, in which the rotation stopper members 97 areembedded. As shown in FIG. 103, the rotation stopper member 97 partiallyprotrudes from the slope 21 b′, (22 a′ or 22 b′) of the disc holdingportion 21 b, (22 a or 22 b) and contacts with the outer edge of thedisc 100 while the disc 100 is held by the disc holding portions 21 a,21 b, 22 a and 22 b. The rotation stopper members 97 are preferably madeof a material that has some elasticity and a large coefficient offriction. For example, rotation stopper members 97 made of rubber arepreferably used.

It should be noted that at least one of the disc holding portions 21 a,21 b, 22 a and 22 b should be provided with the rotation stopper member97 to stop the rotation effectively. However, to prevent theunintentional rotation of the disc 100 with more certainty, the threerotation stopper members 97 are preferably provided as shown in FIG.102.

In this structure, while the disc 100 is held by the disc holdingportions 21 a, 21 b, 22 a and 22 b, the rotation stopper members 97 thatare in tight contact with the disc 100 do not allow the operator torotate the disc 100 so easily. Accordingly, even if the operator triesto rotate the disc 100 intentionally while pressing the disc 100 againstthe shutters 21 and 22, the disc 100 will not rotate. Thus, even ifrelatively stiff dust has adhered to the nonwoven fabric provided forthe shutters 21 and 22, the disc will not get scratched by theoperator's operation such as that described above.

In addition, by providing the rotation stopper members 97, it is alsopossible to prevent the disc 100 from moving inconstantly inside thedisc holding portions.

As shown in FIG. 102, the shutters 21 and 22 include the concaveportions 89, which are used to ultrasonic weld a nonwoven fabric tothose portions of the shutters 21 and 22 that will contact with thesignal recording side of the disc 10. In FIG. 102, the concave portions89 are formed so as to surround the outer periphery of those portions ofthe shutters 21 and 22 that will contact with the signal recording side.The concave portions 89 are also formed inside the concave portions 89that surround the outer periphery. However, the regions where theconcave portions 89 are provided are not limited to those illustrated inFIG. 102 as long as the nonwoven fabric can be adhered to the shutters21 and 22 just as intended. At these concave portions 89, the nonwovenfabric is ultrasonic welded to the shutters 21 and 22. The nonwovenfabric might be partially cured or the resin material of the shutters 21and 22 might partially protrude from the nonwoven fabric during theultrasonic welding process. Even so, when these concave portions 89 areprovided, those cured or protruding portions are received by the concaveportions 89 and do not contact with the disc. Thus, the disc does notget scratched. When a nonwoven fabric is provided, these concaveportions 89 are also preferably formed on the shutters in any of thefirst through eighteenth embodiments described above.

In the first through nineteenth embodiments described above, a nonwovenfabric is ultrasonic welded or adhered to the shutters. However, if thedisc has some anti-scratching structure (e.g., if the signal recordingside of the disc is covered with a stiff hard coating), then thenonwoven fabric does not have to be attached thereto, but the shuttersmay contact with the disc directly. Also, not the entire surface of theshutters has to be in plane contact with the signal recording side ofthe disc, but the shutters may have such a structure that at least aportion of the shutters contacts with the signal recording side of thedisc. That is to say, not the entire surface but just a portion of thesurface of the shutters may be in plane contact with the disc. In thatcase, some anti-scratching structure (e.g., a nonwoven fabric) may beprovided for only that portion being in plane contact with the disc.

In the first through nineteenth embodiments described above, the disc100 to be stored in the disc cartridge has just one signal recordingside. However, a single-sided disc like this is used for illustrativepurposes only. This is because the disc cartridge of the presentinvention has such a structure as to expose one side of the disc andbecause a single-sided disc is best suited to a structure of that type.Thus, even a disc having two signal recording sides may be appropriatelystored in the disc cartridge of the present invention and may be loadedinto a disc drive to write or read a signal thereon/therefrom. It shouldbe noted, however, that where a double-sided disc is stored and housedin the disc cartridge of the present invention, dust may be deposited onthe exposed one of the two signal recording sides. Accordingly, in thatcase, some mechanism for preventing the unwanted dust deposition shouldpreferably be provided.

Also, in the first through nineteenth embodiments described above, thesize of the disc 100 is not particularly specified. However, the presentinvention may be implemented as a disc cartridge for accommodating adisc having a size of 12 cm or any of various other sizes.

Furthermore, in the first through nineteenth embodiments describedabove, the disc cartridge is illustrated as having an outer dimensionthat is slightly greater than the size of the disc. However, the sizerelationship between the disc and the disc cartridge is not limited tothe illustrated one. For example, even when the disc cartridge has anouter dimension that is large enough to store a 12 cm disc therein, thedisc storage portion and the disc holding portions of the disc cartridgemay have their sizes and structures defined in such a manner as to storean 8 cm disc. Such a disc cartridge may be used as an adapter forgetting write and read operations performed on an 8 cm disc by a discdrive for writing or reading a signal on/from a 12 cm disc.

The various features as described for the first through nineteenthembodiments may be combined appropriately. For example, the rotationstopper members as described for the nineteenth embodiment may beprovided for the disc cartridge of the sixteenth embodiment. Also, therecesses for use to collect dust therein as described for the fifteenthembodiment may be provided for the disc cartridge of the sixteenthembodiment. As can be seen, the first through nineteenth embodiments maybe combined in numerous other ways and not all of those possiblecombinations of embodiments have been described herein. However, it isquite possible for those skilled in the art to carry out those variouspossible combinations of embodiments by reference to the description ofthe present application. Thus, it is intended that all of those variouspossible combinations of embodiments fall within the scope of thepresent invention.

The disc cartridge of the present invention can be used particularlyeffectively to store a disc having only one recording side. Thecartridge body thereof has such a structure as to cover only the signalrecording side of the disc and expose the other side thereof. Thus, thecartridge can have a reduced thickness. Also, the shutters thereof areformed in such a shape as to cover just one side of the disc cartridge.Accordingly, the shutters can have a simplified structure and can beformed at a lower cost. In addition, the disc holding portions or diskholding members thereof hold a disc thereon by pressing the disc againstthe shutters or the cartridge body. Thus, the disc will not moveinconstantly inside the cartridge body and no dust will be deposited onthe signal recording side of the disc. Furthermore, since the label sideof the disc is displayed inside the disc window, the disc cartridge canalso have a good design.

Thus, the present invention provides a thinner and highly dustproof disccartridge of a good design that is applicable for use in various typesof disc drives.

What is claimed is:
 1. A disc cartridge comprising: a cartridge bodyincluding a disc storage portion, a chucking opening and a head opening,wherein the disc storage portion has a disc window and a bottom andstores a disc, having first and second sides, therein so that the discis rotatable in the disc storage portion and that the first side of thedisc is exposed through the disc window; the chucking opening is formedon the bottom of the disc storage portion so as to get the disc chuckedexternally; and the head opening is also formed on the bottom of thedisc storage portion so as to allow a head, which reads and/or writes asignal from/on the second side of the disc, to access the second side ofthe disc; a plurality of shutters, which are supported to, and rotatablewith respect to, the cartridge body between the second side of the discand the bottom of the disc storage portion so as to expose or cover thechucking opening and the head opening cooperatively; and disc holdingportions provided at portions of the respective shutters for fixing thedisc onto the shutters or the cartridge body synchronously with amovement of the shutters, by pressing the disc toward the bottom of thedisc storage portion when the shutters covers the chucking opening andthe head opening.
 2. The disc cartridge of claim 1, wherein the shuttersrotate on respective multiple rotation shafts that are provided on thedisc cartridge body.
 3. The disc cartridge of claim 2, wherein therotation shafts are provided in respective portions of the disccartridge body other than the disc storage portion.
 4. The disccartridge of claim 3, wherein the head opening reaches a side surface ofthe cartridge body, and wherein the rotation shafts are provided nearanother side surface thereof that is opposed to the former side surface.5. The disc cartridge of claim 1, wherein the shutters includeinterlocking portions that open or close the shutters while beinginterlocked with each other.
 6. The disc cartridge of claim 5, whereinthe interlocking portions are cam-shaped or gear-shaped portions thatare provided for the respective shutters.
 7. The disc cartridge of claim5, wherein the interlocking portions are belts or links.
 8. The disccartridge of claim 1, wherein the disc storage portion includes: a firstinner surface to be the bottom of the disc storage portion; a secondinner surface that is substantially in a cylindrical shape and thatsurrounds the outer periphery of the disc when the disc is stored in thedisc storage portion, and wherein the second inner surface is partiallynotched so as not to interfere with the operation of the shutters. 9.The disc cartridge of claim 1, wherein the cartridge body includes ashutter storage portion that stores portions of the shutters thereinwhile the shutter exposes the chucking opening and the head opening. 10.The disc cartridge of claim 1, wherein the shutters cover the chuckingopening and the head opening by partially overlapping with each other ina thickness direction of the shutters.
 11. The disc cartridge of claim1, further comprising an elastic member that applies a force in such amanner as to keep the shutters opened or closed.
 12. The disc cartridgeof claim 11, wherein the elastic member is provided in a portion of thedisc cartridge body other than the disc storage portion.
 13. The disccartridge of claim 12, wherein the elastic member has been molded so asto form an integral part of the shutters.
 14. The disc cartridge ofclaim 1, wherein the disc cartridge includes a protective layer forpreventing the disc from getting scratched on portions of the shuttersthat contact with the second side of the disc.
 15. The disc cartridge ofclaim 14, wherein the protective layer is selected from the groupconsisting of an anti-scratching nonwoven fabric, a dustproof nonwovenfabric, an anti-scratching coating layer and a dustproof coating layer.16. The disc cartridge of claim 14, wherein the dirt of the disc isremoved by rotating the disc while the disc is in plane contact with theshutters.
 17. The disc cartridge of claim 14, wherein the dirt of thedisc is removed by the opening or closing operation that is performed bythe shutters to expose or cover the chucking opening and the headopening.
 18. The disc cartridge of claim 1, wherein one of the shuttersis provided with a locking mechanism that fixes the shutters onto thecartridge body while the shutters are covering the chucking opening andthe head opening.
 19. The disc cartridge of claim 18, wherein thelocking mechanism includes: a locking hole that is formed through thedisc cartridge body; and a locking protrusion portion that is providedat one of the shutters so as to engage with the locking hole when theshutters are located at such a position as to cover the chucking openingand the head opening.
 20. The disc cartridge of claim 19, wherein thelocking protrusion portion is provided at the one of the shutters by wayof an elastic member and wherein the elastic member applies a force tothe locking protrusion portion toward the locking hole and makes thelocking protrusion portion engage with the locking hole.
 21. The disccartridge of claim 19, wherein an opening/closing lever for use to openor close the shutters is provided at one of the shutters that isprovided with the locking protrusion portion.
 22. The disc cartridge ofclaim 1, further comprising an erroneous insertion preventing mechanismfor the disc cartridge.
 23. The disc cartridge of claim 22, wherein theerroneous insertion preventing mechanism includes convex portions orconcave portions that are provided on outer side surfaces of thecartridge body so as to be asymmetrically disposed in a direction inwhich the disc cartridge is inserted into an external apparatus.
 24. Thedisc cartridge of claim 19, wherein an opening/closing lever for use toopen or close the shutters is provided at one of the shutters that isnot provided with the locking protrusion portion.